■■MMHMnMH 



I 



RURAL TEXT-BOOK 
SERIES 




PRINCIPLES 

OF 
AGRONOMY 




HARRIS S. STEWART 



Jllili 



L, H. BAI LE 

EDITOR 



WBaaaaaeKoanaj 



-.■-4b. 



XTbe IRural TLcxUBoo\\ Series 

Edited by L. H. BAILEY 



THE PRINCIPLES OF AGRONOMY 



Eht Eural Erxt^Book Series 

Editkd by L. H. bailey 

Ma7in, Beginnings in Agriculture, 

Warren, Elements of Agriculture. 

Warren, Farm Management. 

Lyon, Fippin and Buckman, Principles of 
Soil Management. 

J. F. Duggar, Southern Field Crops. 

B. M. Duggar, Plant Physiology, with 
special reference to Plant Production. 

Harper, Animal Husbandry' for Schools. 

Montgomery, The Corn Crops, 

Wheeler, Manures and Fertilizers. 

Livingston, Field Crop Production. 

Widtsoe, Principles of Irrigation Prac- 
tice. 

Piper, Forage Plants and their Culture. 

Hitchcock, A Text-book op Grasses. 

Gay, The Principles and Practice of 
Judging Live-Stock. 

White, Principles of Floriculture, 



THE PRINCIPLES OF 
AGRONOMY 



A TEXT-BOOK OF CROP PRODUCTION FOR HIGH- 
SCHOOLS AND SHORT-COURSES IN 
AGRICULTURAL COLLEGES 



BY 

FEANKLIN S: HARRIS, Ph.D. 

PE0FE8S0K OF AGKONOMY AND DIRECTOR OF THE SCHOOL OF AGBICULTtTKAL 
ENGINEERING, UTAH AGRICULTURAL COLLEGE 



GEORGE STEWART, B.S. 

INSTRUCTOR IN AGRONOMY, UTAH AGRICULTURAL COLLEGE 



THE MACMILLAN COMPANY 
1915 

All rights reserved 



YV\ 



vi Preface 

ences have been made to state experiment station pub- 
lications, since many of them are not available. 

The teaching of agriculture is valuable only as it 
is made practical. It is suggested, therefore, that stu- 
dents work in the laboratory and field as much as 
possible in order to become directly familiar with soils, 
crops, and applications of principles instead of relying 
solely upon what the text says about them. 

The authors are indebted to a number of their col- 
leagues at the Utah Agricultural College for encour- 
agement and friendly criticism during the preparation 
of this book. They are under special obligation to 
President J. A. Widtsoe, Director E. D. Ball, Pro- 
fessor N. A. Pederson, and Messrs. A. F. Bracken, 
C. L. Anderson, and N. I. Butt, all of whom have 
read the manuscript and offered valuable suggestions. 

FRANKLIN S. HARRIS, 
GEORGE STEWART. 
Logan, Utah, 

May 1, 1915. 



CONTENTS 

CHAPTER I 

PA6K8 

Introductory ......... 1-5 

What is agriculture ? 1 i Agriculture and the sciences, 
2 ; Agriculture and the industries, 2 ; Opportunities in 
agriculture are varied, 3 ; Divisions of agriculture, 4 ; 
Phases of agTonomy, 4 ; Scope of this book, 4. 

PART I. THE PLANT 

CHAPTER II 

Thk Plant and Its Environment 9-22 

Factors of plant growth, 10 ; Length of season, 12 ; 
Frost, 13 ; Temperature, 14 ; Water, 16 ; Sunlight, 18 ; 
Wind, 19 ; Soil, 19 ; Pests, 20 ; Adapted crops, 21. 

CHAPTER III 

Plant Structure ........ 23-38 

Cells, 23 ; Tissues, 25 ; Kind of plant, 26 ; Crop plants, 
26 ; Plant parts, 27 ; The root, 27 ; The stem, 30 ; The 
leaf, 35 ; The flower, 35 ; The seed, 37 ; Buds and 
branches, 37 ; Underground stems, 37. 

CHAPTER IV 

Plant Functions 39-49 

Growth, -39 ; Respiration, 41 ; Photosynthesis, 42 ; 
Osmosis, 44 ; Transpiration, 46 ; Translocation, 48 ; 
Transportation, 48 ; Response, 49. 



viii Contents 



CHAPTEU V 

PAGES 

The Plant as a Factory 50-63 

Interdependence of plants and animals, 51 ; Depend- 
ence of man on plants, 51 ; Domestication, 53 ; Plant 
compounds, 54 ; Flavors, 54 ; Water, 55 ; Carbohydrates, 
55 ; Protein, 56 ; Ash, 56 ; Fats and oils, 56 ; The plant 
factory, 57; Animal concentration, 59; Storage, 59; 
Harvest, 61 ; Control of the harvest, 62. 



PAET II. THE SOIL 

CHAPTER VI 

What the Soil Is 67-69 

Definition, 67 ; Permanence of soils, 68 ; Economic 
importance of the soil, 68 ; Conservation of the soil, 68 ; 
Need of better soil management, 69. 

CHAPTER Vll 

Origin and Formation of Soils 70-80 

Minerals and rocks, 70 ; Soil-forming minerals, 70; 
Quartz, 71 ; The feldspars, 71; Hornblende and pyrox- 
ene, 71 ; Mica, 71 ; Chlorite, 72 ; Zeolites, 72 ; Calcite, 
72 ; DolQmite, 73 ; Gypsum, 73 ; Apatite, 73 ; Soil-form- 
ing rocks, 73 ; Methods of soil formation, 74 ; Action of 
heat and cold, 74 ; Action of v?ater, 75 ; Ice, 76 ; The 
atmosphere, 78 ; Plants and animals, 78 ; Classification 
of soils, 79. 

CHAPTER VIII 

Physical Properties of the Soil 81-89 

Soil texture, 81 ; Groups according to texture, 82 ; Re- 
lation of texture to water-holding capacity, 83; Soil 
structure, 83 ; How to modify structure, 84 ; Specific 
gravity of soils, 86 ; Air in the soil, 86 ; Heat of the soil, 
87 ; The organic matter of the soil, 88 ; Maintaining the 
organic matter, 88. 



Contents ix 



CHAPTER IX 

PAGES 

The Water of the Soil ....... 90-97 

Origin of soil water, 90 ; Variations in soil moisture, 
91 ; The condition of soil moisture, 91 ; Free water, 91 ; 
Capillary water, 92 ; Hygroscopic water, 92 ; Other crit- 
ical points, 93 ; Quantity of water in field soils, 9.3 ; 
Methods of expressing the quantity of water, 94 ; Loss 
of soil moisture, 9-1 ; Need for preventing evaporation, 
94; The water-table, 95; The movements of soil mois- 
ture, 96 ; Use of soil water, 90 ; Quantity of water used 
by plants, 96. 



CHAPTER X 

The Control of Soil Water 98-117 

Irrigation : Increasing the soil moisture, 98 ; Sources 
of water supply, 100 ; Measurement of water, 102 ; Meth- 
ods of applying water, 103 ; The amount of water to use, 
104 ; When to irrigate, 105 ; Over irrigation, 106 ; Need 
for economy, 106. Drainage : Removing excessive 
water, 107 ; Removing alkali, 108 ; Benefits of drainage, 
108 ; Kinds of drainage, 109 ; Installing the drains, 110. 
Dry-farming: Scope of dry-farming, 111; The ques- 
tion of rainfall. 111; Dry-farm soils, 113; Dry-farm 
crops, 115; Tillage methods, 116. 



CHAPTER XI 

Plant-food of the Soil ....... 118-124 

What plants use from the soil, 118 ; Composition of 
soils, 119 ; The analysis of soils, 120 ; Available and re- 
serve plant-food, 121 ; Making plant-food available, 121 ; 
Quantity of plant-food removed by plants, 121 ; Plant- 
foods that are scarce, 122 ; Exhausticm of the soil, 123 ; 
Losses in plant-food, 123 ; Plant-food in organic matter, 
124 ; Relation of plant-food to value of a soil, 124. 



Contents 



CHAPTER XII 

PAGES 

Manures and Fertilizers 125-137 

Types of fertilizers, 126 ; How to determine fertilizer 
needs, 126; Nitrogen fertilizers, 127; Nitrogen fixation, 

128 ; Phosphorus fertilizers, 128 ; Potassium fertilizers, 

129 ; Lime, 129 ; Indirect fertilizers, 130 ; Home-mixing 
of fertilizers, 130 ; Value of farm manure, 131 ; Kinds 
of farm manure, 132 ; Losses in manure, 133 ; Handling 
farm manure, 131 ; How to fertilize different crops, 136 ; 
Green manures, 136. 

CHAPTER XIII 
Organisms of the Soil ....... 138-144 

Kinds of soil organisms, 138; Bacteria, 139; The 
number of bacteria in the soil, 139 ; Kinds of bacteria, 
139 ; How bacteria grow, 140 ; Relation to humus for- 
mation, 141 ; Relation to nitrogen, 141 ; The fixation of 
nitrogen, 142 ; Nitrification and denitrification, 143 ; 
Bacteria and the farmer, 144. 

CHAPTER XIV 
Tillage and Crop Rotations ...... 145-153 

Improving soil structure, 145 ; Controlling weeds, 147 ; 
Covering manure and plant residues, 148 ; Conserving 
moisture, 149 ; Tillage of various crops, 150 ; Reasons 
for rotation of crops, 151 ; Methods of crop rotation, 152. 

CHAPTER XV 

Special Soil Problems 154-163 

Alkali : Kinds of alkali, 155 ; Effect of alkali on plant 
growth, 156 ; Reclamation of alkali lands, 156. Acidity : 
Indicators of a soil acidity, 157 ; Correction of soil 
acidity, 157. Erosion : Methods of preventing erosion, 
158. Blowing : Prevention of blowing, 160. Methods 
of judging soils : Indicator value of native vegetation, 
161 ; Topography of the land, 161 ; Depth and structure 
of the soil, 162 ; Chemical analysis, 162 ; Mechanical 
analysis, 163 ; Productivity, 163. 



Contents xi 



PART III. FIELD CROPS 
CHAPTER XVI 

PACiES 

Wheat 167-190 

Relationships, 1(38 ; Roots, 168 ; The plant above 
ground, 170 ; The kernel, 170 ; Varieties, 171 ; Distri- 
bution and adaptation, 173 ; Preparation of seed-bed, 
175; Seed and seeding, 175 ; Harvesting, 178 ; Diseases, 
179 ; Closed smut, 179 ; Loose smut, 180 ; Rust, 180 ; 
Insects, 180 ; Weeds, 181 ; Quality in wheat, 182 ; Uses 
and value, 183 ; Storage, 184 ; Elevators, 186 ; Market- 
ing, 187 ; Prices, 188. 

CHAPTER XVII 

Corn or Maize 191-207 

Relationships, 191 ; Roots, 192 ; The culms, 193 ; The 
leaves, 193 ; The flower, 194 ; The ear, 194 ; Types, 195 ; 
Dent corn, 195 ; Plint corn, 196 ; Sweet corn, 196 ; Pop 
corn, 196 ; Soft or flour corn, 197 ; Pod corn, 197 ; Va- 
rieties, 197 ; Distribution, 197 ; Factors in production, 
198 ; Adaptation, 198 ; Preparation of the seed-bed, 199 ; 
Seed and planting, 200 ; Treatment of the growing crop, 
201 ; Harvesting, 203 ; Silage, 203 ; Enemies, 204 ; Uses 
and value, 204 ; Storage and marketing, 205. 

CHAPTER XVIII 
Other Cereals 208-223 

Oats : Origin and relationships, 208 ; Description, 209 ; 
Distribution, 210 ; Varieties, 212 ; Seeding and cultiva- 
tion, 212 ; Harvesting and marketing, 212 ; Uses, 213 ; 
Enemies, 214. Barley : Description, 215 ; Distribution 
and adaptation, 216 ; Sowing and cultivation, 216 ; Har- 
vesting and marketing, 217 ; Enemies and uses, 218. 
Bye : Description and distribution, 219 ; Handling the 
crop, 220 ; Uses, 220. Bice : Description and distribu- 
tion, 221 ; Uses, 221. Enemies: Description and use, 
222. Buckwheat : Description, distribution, and uses, 
222. 



xii Contents 



CHAPTER XIX 

PAGES 

Potatoes 224-240 

Origin, 224 ; Relationships, 225 ; Description, 225 ; 
Varieties, 227 ; Distribution and adaptation, 228 ; Prep- 
aration of land, 230 ; Seed, 231 ; Cutting and planting, 
233 ; Treatment during growth, 234 ; Harvesting and 
marketing, 235 ; Storage, 235 ; Weeds and insects, 236 ; 
Diseases, 236 ; Use and value, 239. 

CHAPTER XX 

Root Crops 241-255 

Stig ar -beets : History,, 241 ; Description, 243; Adap- 
tation and distribution, 243 ; Preparation of the land, 
seed, and seeding, 245; Treatment during growth, 247 ; 
Diseases, 248 ; Insects, 249 ; Harvesting, marketing, and 
storage, 249 ; Use and value, 250 ; Manufacture of sugar, 
251. Mangel-ivurzels : Description, 251 ; Use, 2-52 ; 
Culture, 252. Turnips and Rutabagas : Description, 
253 ; Culture, 253 ; Value, 254. Carrots : Description, 
264 ; Culture and use, 255. 

CHAPTER XXI 

Alfalfa 256-270 

Name and origin, 256 ; Relationships, 258 ; Roots, 
258 ; Stems and leaves, 259 ; Flowers and seed, 260 ; 
Varieties, 261 ; Distribution and adaptation, 261 ; Prep- 
aration of the land and seeding, 263 ; Treatment during 
growth, 263 ; Harvesting, 264 ; Storage, 265 ; Use and 
value, 266 ; Mixtures, 267 ; Enemies, 268 ; Seed produc- 
tion, 269. 

CHAPTER XXII 

The Clovers and Other Legumes ..... 271-285 
Bed clover : Description, 272 ; Distribution and adap- 
tation, 272 ; Culture, 273 ; Use and value, 273. Other 
clovers : Alsike clover, 274 : White clover, 274 ; Sweet 
clover, 274 ; Crimson clover, 275. Field Peas : Descrip- 



Contents 



Xlll 



tion and adaptation, 275 ; Sowing, 276 ; Culture and 
harvesting, 277; Use, 277. Beans: Description, 278; 
Culture, 278 ; Use, 280. Cowpeas : Description, 280 ; 
Culture, 282. Soybeans : Description, 282 ; Cul- 
ture, 283. Miscellaneous Legumes : Vetch, 284 ; Other 
legumes, 284. 

CHAPTER XXIII 

Grasses 286-301 

Timothy : Description, 288 ; Adaptation, 289 ; Cul- 
ture, 289 ; Use and value, 291 ; Enemies, 292. Bedtop : 
Description, 292 ; Adaptation, 292 ; Culture, 293 ; Value 
and use, 293. Kentucky Blue-grass : Description, 293 ; 
Adaptation, 294 ; Culture, 294 ; Use and value, 294. 
Orchard- grass : Description, 29.5 ; Adaptation, 29.5 ; Cul- 
ture, 295 ; Value and use, 296. Smooth Brome-grass : 
Description, 297 ; Adaptation, 297 ; Culture, 297 ; Value 
and use, 298. Other grasses: Tall meadow oat-grass, 
299 ; Bermuda-grass, 299 ; Johnson-grass, 300 ; Miscel- 
laneous grasses, 301. 



CHAPTER XXIV 

Pastures, Meadows, and Soiling Systems 

Definition, .302 ; Kinds of pasture, 302 ; A good pas- 
ture, 303 ; Importance, 303 ; Native grass, 304 ; Crop 
plants, 304 ; Mixtures, 304 ; For different animals, 307 ; 
Condition of pastures, 308 ; Improving pastures, 308 ; 
Over-stocking, 309 ; Management, 310 ; Meadows, 311. 
Soiling : Use, 312 ; Value, 312; Soiling crops, 316. 



302-317 



CHAPTER XXV 

Sorghums and Millets 

Sorghum: Origin, 318; Relationships, 320 ; Descrip- 
tion, 320 ; Varieties, 322 ; Distribution and adaptation, 
323 ; Preparation of seed-bed and seeding, .325 ; Treat- 
ment during growth, 325 ; Harvesting, 326 ; Use, 327 ; 
Enemies, 328 ; Storage and marketing, 328. Sudan- 
grass : Description, 329 ; Culture, 329. Millets : Rela- 
tionship and description, 330 ; Culture and value, 330 ; 
Other types, 331. 



318-3.32 



xiv Contents 



CHAPTER XXVI 

PAGES 

Fibers and Miscellaneods Crops ..... 333-352 

Fibers : Cotton. History, 333 ; Relationships, 334 ; 
Description, 335 ; Adaptation, 335 ; Culture, 336 ; Har- 
vesting and marketing, 337 ; Use, 337. Flax: Descrip- 
tion, 338 ; Adaptation, 338 ; Culture, 338 ; Use and 
value, 340. Other fibers : Hemp, 340 ; Miscellaneous 
fibers, 341. Miscellaneous crops : Cabbage and kohl- 
rabi, 342 ; Rape, 343 ; Kale, 343 ; Enemies, 343. To- 
bacco : Distribution, 345 ; Culture, 345 ; Curing and 
marketing, 345 ; Sugar-cane, 346 ; Sweet potatoes, 347 ; 
Fruits, 349 ; Truck crops, 349 ; Timber crop, 351 ; Other 
crops, 351. 

CHAPTER XXVII 

Improvement of Crop ....... 353-365 

What is improvement ? 354 ; Ideal sought, 356 ;' Cul- 
tivation, 357 ; Seed-testing, 367 ; Reproduction, 359 ; 
Variation, 359 ; Natural selection, 360 ; Artificial selec- 
tion, 360 ; The be.st plants should be chosen, 361 ; Va- 
riety tests, 362 ; Steps in breeding, 362 ; Crossing, 362 ; 
Mendel's law, 363 ; Importance of large numbers, 364 ; 
Better seed, 364. 

CHAPTER XXVIII 

Weeds 366-378 

Definition, 366 ; Classification, 367 ; Occurrence, 368 ; 
Dissemination, 364 ; Losses from v^eeds, 370 ; Preven- 
tion, 372 ; Eradication, 373 ; General principles, 375 ; 
Herbicides, 376; Summary, 377. 

PART IV. FIELD MANAGEMENT 

CHAPTER XXIX 
Planning the Farm ........ 381-386 

Plan should be stable, 381 ; Number of enterprises, 
383 ; The farmstead, 383 ; Arrangement and number of 
fields, 384 ; Size and shape of fields, 384 ; Fences and 
ditches, 385 ; Use of waste places, 386. 



Contents xy 



CHAPTER XXX 

PAGES 

What Crops to Grow 387-391 

Crop adaptation, 387 ; Diversity of crops, 388 ; CroQ 
specialties, 389; Conditions for various crops, 391; 
Work in producing various crops, 391. 



CHAPTER XXXI , 

Equipment of the Farm ....... 392-399 

The farmer as a mechanic, 392 ; Extremes in farm 
equipment, 393 ; Machines that get out of date, 394 ; 
Machines that are seldom used, 395 ; Size of machinery, 
395 ; The duty of machinery, 395 ; Depreciation, 396 ; 
Caring for machinery, 397 ; Suitable farm buildings, 398. 

CHAPTER XXXII 

Factors of Success in Crop Production . . . 400-406 

Size of farm, 300 ; Capital, 401 ; Proper type of farm- 
ing, 402 ; Good management, 402 ; Keeping records, 
403 ; Profits to a farmer vs. yields to the acre, 403 ; 
Profits from man and horse labor, 404 ; Understanding 
each crop, 404 ; Markets, 404. 

APPENDICES .... 407-430 

Addresses of Agricultural Colleges and Ex- 
periment Stations and of the United States 
Department of Agriculture . . . 408 

Laboratory Guides 411 

Fertility in Farm Pi'oduce .... 412 

Composition, Amount, and "Value of Manure 
Produced by Different Kinds of Farm 

Animals 413 

Weights and Measures ■ 414 

Quantity of Seed Planted to the Acre . . 416 

Most Common Weights of Seeds to the 

Bushel 417 



Appendix 


A. 


Appendix 


B. 


Appendix 


C. 


Appendix 


D. 


Appendix 


E. 


Appendix 


F. 


Appendix 


G. 



XVI 



Contents 



PAGE 

Appendix H. Measuring Rules 418 

Appendix I. Rules for Measuring Hay in the Stack . . 419 

Appendix J. Wheat Harvest Calendar .... 420 
Appendix K. Prices of Wheat on a Chicago Market (1863- 

1910) 421 

Appendix L. Crop Statistics for Continental United States 423 

Appendix M. Plowing as affected by Shape of the Field . 424 
Appendix N. Average Depreciation a Year and Cost to 

the Acre for Farm Machinery . . . 425 

Appendix O. Glossary 426 



THE PRINCIPLES OF AGRONOMY 



THE PRINCIPLES OF AGRONOMY 



CHAPTER I 
INTRODUCTORY 

Agriculture is so broad in its scope and practice, that 
it is related to almost every branch of human learning. 
All the industries and professions of man are in some 
way connected with the land and its products. The 
welfare of manufacturer, merchant, railroad man, lawyer, 
and doctor is so dependent on agricultural prosperity 
that these men are necessarily interested in this great 
subject. Since agriculture embraces such a wide field, 
it is necessary to define and subdivide, in order to obtain 
a clear idea of its various branches. 

1. What is agriculture? — Agriculture may be defined 
as the art, the science, and the business of producing 
plants and animals for economic purposes. 

As an art, it embraces aFnowledge of the way to per- 
form the operations of the farm in a skillful manner, 
but does not necessarily include an understanding of the 
principles underlying farm practices. The ability to 
plow well, to make a good stack of hay, and to handle 
live-stock indicates training in the handicrafts of agri- 
culture. 

The science of agriculture deals with the principles 
underlying the production of plants and animals, with- 
out regard to skill in the practices of farming. A person 
B 1 



2 The Principles of Agronomy 

may understand the methods by which hay is digested 
in the stomach of a cow, and how milk is secreted ; he 
may be familiar with the composition of milk and the 
processes it undergoes in the manufacture of butter or 
cheese ; and still he may not know how even to milk a 
cow. He has training in the underlying scientific prin- 
ciples of agriculture, but not in the art or handicraft. 

Agriculture is a business, since it is practiced primarily 
as a means of securing a living. Usually a farmer is not 
interested in the art and science of agriculture except as 
they contribute to his making a better livelihood. Science 
helps him to understand why he does certain things, and 
gives him a foundation for his practices ; he acquires skill 
in the practices in order to increase production and, 
through it, to extend his income. 

2. Agriculture and the sciences. — The assertion is 
sometimes made that if a person were familiar with all 
the sciences, he would not need to study agriculture. 
This is probably true, but no one person is able to master 
all the sciences ; even if he were able to do so, he would 
need to learn some of the applications of science to the 
land before finishing his studies of pure science. 

The real condition, however, is that those who have 
most to do with the land have little time for extensive 
study of science, although they desire a brief knowledge 
of some of the principles underlying the industry in which 
they are engaged. This justifies the teaching of agri- 
culture even to those who have had little training in the 
so-called pure sciences. The better one understands the 
natural and social sciences, however, the better will one 
be able to comprehend the principles and problems of 
agriculture. 

3. Agriculture and the industries. — Agriculture is at 
the very foundation of all industries. Manufacturing, 



Introductory 3 

mining, and commerce are dependent on the products of 
the soil for their existence ; indeed, the very Hfe of man 
himself would be impossible if the soil did not directly 
or indirectly yield him food. The advance of civiliza- 
tion and the development of industrial enterprises are 
limited by the agricultural conditions of the world. Agri- 
culture, instead of being a problem merely for those en- 
gaged directly in its practice, is a world problem affecting 
all the activities of man. It is evident, therefore, that 
it merits serious consideration. 

The farm, in addition to being a place where a great 
industry is condvicted, is a home for those engaged in 
this industry. It should, therefore, be considered not 
entirely from the point of view of economic efficiency, 
but of social efficiency also, as the home of that part 
of the coming generation which will probably have 
most to do with the future welfare of the nation. Agri- 
culture, as a consequence, has social and educational 
aspects quite as important as its scientific and economic 
phases. 

4. Opportunities in agriculture are varied. — The most 
important opportunities are those connected with the 
work on the land in its various phases. Never in history 
has the land called with a louder voice than at present, 
for young men of intelligence, industry, and training. 
There are opportunities on every hand for him who knows 
how to use the forces of nature, and who can secure joy 
and satisfaction in being a direct producer. 

Other phases of agriculture, such as teaching it in the 
schools, engaging in demonstration and experimental 
work for the states and the government, and working as 
an expert adviser for corporations, are assuming greater 
importance every year, and offer good opportunities to 
young men of ability and training. 



4 The Principles of Agronomy 

5. Division of agriculture. — Agriculture may be sub- 
divided in many ways. It may be classed as intensive 
or extensive, specialized\ or diversified, exploitive or 
restorative, tropical or temperate ; or it may be divided 
according to the source of income. For instructional 
purposes in agricultural colleges, it has often been divided 
into three main parts : agronomy, animal husbandry, 
and horticulture. 

The subject of agronomy has usually included a study 
of^soils, field crops, and farm management. Under animal 
husbandrypEhe various phases of the live-stock indus- 
try, including dairying, have been studied. The study 
of horticulture has included the production of fruits, 
vegetables, and flowers. 

In addition to these three applied divisions, there are 
also a number of scientific divisions, such as entomology, 
chemistry, and plant and animal pathology. Each of 
these bears a relation to all three of the applied divisions. 
It is difficult, therefore, to find a subdivision of agriculture 
that is logical and at the same time entirely practical, 
since the difi^erent branches are so closely interrelated. 

6. Phases of agronomy. — The present volume deals 
with that phase of agriculture sometimes called agronomy. 
The meaning of this word is not widely known outside 
of the schools, and even there it is used somewhat loosely. 

It comes from two Greek words meaning " the use of (.J 
fields." At present, it is usually understood to mean the 
management of the land in the production of field crops. 
It is sometimes divided into three distinct phases : soils, 
crops, and farm management. The term " agronomy " 
may be applied to any one of these branches. 

7. Scope of this book. — To give the beginner in 
agricultural study a general idea of the principles of suc- 
cessful production of crops, and to furnish him a basis for 



Introductory 5 

study in the other branches of agriculture, is the object 
of the present volume. 

Part I discusses the principles of plant growth, and 
will be of service to students who later take up horticulture 
as well as to those studying agronomy. In Part II, a 
study is made of the soil and its management. This 
part is likewise fundamental to horticulture as well as to 
agronomy. Part III is devoted entirely to the study of 
field crops ; and in Part IV, numbers of problems relating 
to field management are discussed.. Some of these also 
apply to other phases of agriculture. 



PART I 
THE PLANT 



CHAPTER II 
THE PLANT AND ITS ENVIRONMENT 

On every side are evidences that plants (Jjear more or 
less definite relations to the nature of their surroundings. 
An environment that favors one crop may prevent the 
culture of another. Tropical plants do not thrive in 
temperate or frigid zones ; neither do lilies grow in deserts, 
nor roses on barren cliffs. 

Great forests spread for hundreds of miles over cer- 
tain sections ; wide grassy plains stretched almost end- 
lessly east of the Rockies before settlement ; valleys in 
the West were covered with sagebrush, except for patches 
of willows or Cottonwood along the streams, or for rushes 
and sedges in the sloughs. In many sections scrub oak 
covers the foothills ; groves of quaking aspens line the 
swales in the mountains ; pines and spruces cover the 
shady sides of higher nidges. This grouping has not come 
by chance. Colonies of plants grow up only where condi- 
tions are so favorable to the particular plant that others are 
crowded out. 

Farmers plow and harrow because plants grow better 
in tilled soils. They apply irrigation water and manure 
to aid plant growth. Weeds are removed that the crop 
may have more room. The plant as well as the physical 
conditions in which it lives deserves attention in this 
respect. 

9 



10 The Principles of Agronomy 

8. Factors of plant growth. — In general, there are 
six factors which must be favoral^le in order for plants to 
make the best growth. These are: (1) a home, or place 
in which to find lodging and support, (2) water, (3) heat, 
(4) light, (5) oxygen, and (6) plant-food. The general 
environment determines the character of the vegetation 
(Figs. 1-3). _ 

Fine soil is the medium of growth for agricultural 
plants, though some species flourish in water or on rock. 
The quantity of available water determines the kind of 
plant that may grow in a given spot and the degree of 
development it may attain. A proper degree of warmth 
is essential to germination and to growth. Most plants 
require sunlight, though a few do better in the shade. All 
living cells must have oxygen in order to carry on their 
functions. Lack of air in over-wet soils kills some plants. 
Certain soils lack mineral plant-food in a soluble condi- 
tion and, therefore, produce poor yields if not fertilized. 
Carbon dioxide, a gaseous plant-food, comes from the 
air. 

Of these six factors, man can control but two : (1) the 
water supply of soils, and (2) the plant-food available. 
As regards a given spot, man can do little that will influ- 
ence heat, light, oxygen, and depth or texture of soil. 
His method of control in respect to these depends on his 
power to change his place of abode and, by so doing, to 
select a district having desirable climate and soil. Length 
of season and daily temperature, together with the kind 
of soil, determine the degree of warmth. Clear or cloudy 
weather regulates the sunshine and light. Rainfall and 
winds supplemented by irrigation, drainage, and tillage 
are the factors controlling the water supply. The fineness, 
depth, uniformity, and fertility of the soil measure both 
the plant-food and the opportunity for root development. 



The Plant and its Environment 



11 




12 The Princijjles of Agronomy 

Cropping systems aid materially in causing plants to 
respond properly, while the plant is the subject on which 
these forces interact. 

Insects, rodents, weeds, and plant diseases are pests 
to be reckoned with in crop production. They are 
nuisances, and as such are counted negative or hindering 
factors. 

9. Length of season. — Of the factors controlling the 
distribution of crops in the United States, length of season 
is one of the most powerful. Between the Gulf of Mexico 
and Canada are several well-marked belts of production. 
Of course, no single factor alone accounts for this. Al- 
though moisture, soil, and daily range of temperature 
count for much, they cannot overcome the injurious 
effect of a short growing-season that causes crops from 
the South to fail when moved into the North. That 
^ wheat, oats, and barley have shorter periods of growth 
than potatoes and corn is well known. Cotton requires 
seven or eight months without a frost, while barley or rye 
can get on with a season having only two or four months 
between frosts. Oranges and bananas are not grown 
save in semi-tropical climates where the growing-season 
lasts almost the whole year. Coconuts are produced 
only in tropical regions ; corn extends over a rather broad 
area, from the tropics well into the temperate zones. 
This power of adaptability comes largely from the power 
of corn to adjust itself to shorter growing-seasons. By 
the selection of early-maturing plants, corn-growing has 
gradually extended well up toward the Canadian bound- 
ary. All crops have some power of changing the time 
of growth to suit the seasons of a new district into which 
they are carried. A crop that thrives under certain condi- 
tions will usually grow under others less favorable. Cot- 
ton ai^d cowpeas are confined almost entirely to the sec- 



The Plant and its Environment 13 

tion of the United States south of the thirty-seventh degree 
of latitude. Timothy and red clover are widely grown 
north of this parallel, but not in the South. Potatoes 
are grown in every state, but profitable potato-growing 
is limited to the states in the North ; corn does best in 
the central part. The question of seasonal adaptability 
is one of profitable production rather than of successful 
growth. Although corn grows well north and south of 
the " corn belt," other crops pay better at the extremes 
and they replace it. In the intermediate regions, corn 
is the most profitable crop to grow. It is not so much 
that one crop does not pay, as that another pays better. 
Economical problems enter into agriculture and disturb 
our survey of crop response. An examination of the 
areas in which a crop is grown extensively will show the 
general boundaries of climate and soil that cause one crop 
to supplant another. 

Abbe ^ estimates that variations in climate over areas of 
100 square miles have never caused more than a 50 per 
cent fluctuation in crop yields, and not over 5 per cent 
for the whole United States. Though in moving a crop 
from one section to another length of season counts for 
much, very little can be attributed to it in a given sec- 
tion. This is largely due to the tendency of a climate 
to vary little when long periods are considered. Oc- 
casionally, however, abnormal seasons occur and crops 
that have done well are killed by untimely frosts. 
Tender plants, if not killed, are nipped and retarded in 
growth. 

10. Frost. — Many succulent plants, such as corn and 
melons, are frost-bitten when the temperature drop is but 
slightly below freezing. Hardy crops like rye, barley, 
and wheat are not readily injured even by rather sharp 

1 Weather Bureau Bui. 36, p. 364. 



14 The Principles of Agronomy 

frosts. Alfalfa and potatoes droop after a slight frost, 
but grass and wheat show no sign of injury. Many 
orchardists, maintaining that it is not the frost but sudden 
thawing that kills fruit buds, choose land that slopes 
away from the morning sun in order to avoid immediate 
thawing ; but this is probably an error. Large bodies of 
water hold latent heat ; breezes prevent cold air from set- 
tling in one spot ; large running streams seem to carry 
away the cold air. At any rate, frosts are less likely 
to occur in sections with good air drainage. 

When stems or buds freeze, water is drawn out of the 
cells into the spaces between and there frozen. Some- 
times a sudden drop in temperature will freeze the whole 
plant just as it is. Death from freezing is the result of 
the withdrawal of water from the plasma membrane to 
form ice crystals. When extremely severe, frosts may 
rupture the bark, exposing wood. Frozen plants have 
a wilted or blighted appearance as if injured by excessive 
drouth or heat. A day or so after a frost, the injured 
leaves look as though they had been scorched by a fire 
that was too close. 

Records of a district for a number of years show about 
how late in the spring and how early in autumn frosts 
may be expected. These will vary some, but, as already 
pointed out, not so widely as to prevent a new settler 
from anticipating what crops will mature; provided, 
of course, that he knows how long the crop requires 
and how hardy it is. General farm practice in the 
locality will gradually readjust itself to meet climatic 
demands. Farmers in established districts do not go 
far wrong in regard to time of planting and choice of 
crops. 

11. Temperature. — After length of season, daily 
range of temperature is the chief consideration affecting 



TJie Plant and its Ermroiiment 



15 




16 The Principles of Agronomy 

heat supply. Days are practically as warm in the Great 
Lakes region or in the Great Basin as they are at New 
Orleans, but only for a few hours. Mornings, evenings, 
and nights are much cooler, whereas in the South nights 
as well as days keep warm. Many plants are sensitive to 
a lowering of temperature even though it remains several 
degrees above freezing. On this account, daily fluctua- 
tions are of considerable importance. 

Some evidence seems to indicate that total heat found 
by multiplying the temperature by the length of the season 
determines the growth of some plants. Duggar^ cites 
one case in which yields of date palms increased with the 
total heat. Fall and spring wheat seem to use about 
the same quantity of heat for ripening. Spring grain has 
a shorter but warmer growing period. 

As elevation increases, temperature decreases. Going 
from low to higher land is nearly equivalent to moving 
northward or southward from the equator. High moun- 
tains in the tropics show all gradations of vegetation 
found in passing from tropical to arctic regions. Many 
peaks near the equator are covered with perpetual snow. 
Aside from the temperature change produced, in- 
creased elevations seem to have little influence on 
plant growth if soil and moisture relations are equally 
favorable. 

12. Water. — Every person at all familiar with plants 
has noticed the effect of abundant moisture on them. 
How green the foothills are in early spring, and how brown 
they become in summer after extended periods of drouth. 
When lawns begin to lose their uniform green color, they 
need water. A hose is essential to a good lawn almost 
everywhere. House-plants must be watered frequently ; 
greenhouse plants are usually sprinkled in order to keep 

1 Duggar, Plant Physiology, p. 406. 



Tlie Plant and its Environment 17 

the air as well as the soil moist. Outdoors, particularly 
in arid regions, plants require water. When rains are 
infrequent, irrigation is practiced wherever water is to be 
had at reasonable expense. 

Hunt ^ cites an Illinois record of the influence of water 
on the yield. One year when the rainfall during the grow- 
ing-season was 13 inches, the yield of corn was 32 bushels 
an acre ; the next season with 22| inches gave 94 bushels. 
The same land was used in both instances and other condi- 
tions seemed equal. Green growth continues in moist 
glades after higher lands have become dry. Too much 
water, however, fills up the soil spaces and shuts out the 
air necessary to plant roots. Very wet soils are fatal to 
many plants, but others do not thrive unless almost 
immersed in water. Cresses and seaweeds are examples 
of water-loving plants. Some crops, such as rice, cane, 
cranberries, and redtop, do best in soaked soils. On the 
other hand, alfalfa and the potato suffer quickly from 
standing water. Neither, however, is a drouth-lover, 
though long roots enable alfalfa to be drouth-resistant. 
Cacti, some grasses, and many weeds are able to endure 
extremely hot, dry weather for long periods. All plants, 
then, must have water in varying quantities. Cultivated 
plants, in general, require moderate amounts. 

Since either too little or too much moisture injures 
ordinary crops, irrigation is practiced to supplement the 
rainfall when it is insufficient for profitable yields, and 
drains are laid to remove excess water from the soil. So 
important has irrigation become in dry sections, that 
immense reservoirs, long canals, expensive diversion dams, 
and tunnels have been built to get water to farming lands. 
Throughout arid regions, scarcity of water, more than 
anything else, limits crop yields. Dry-farming is an 

1 Cereals in America, p. 207. 
C 



18 The Principles of Agronomy 

unending struggle against evaporation, and heavier rain- 
fall is a theme of constant prayer. 

Not all the effects of low rainfall are harmful. Irri- 
gation enables the farmer to apply water to one crop and 
withhold it from another, thereby hastening maturity or 
controlling the size and quality of the harvest. Wheat 
long accustomed to dry, hot weather loses part of its 
hardness when grown in moist climates. Excessive water 
injures the cooking quality of potatoes, and causes many 
other crops to be too succulent. 

Lands wet in late spring do not warm up sufficiently 
to permit sowing to early crops. Drying the soil cools 
it because of the heat used in evaporation. Conversely, 
soils that are dry and bare, especially sandy ones, heat 
to abnormal temperatures which are harmful to ordinary 
plants. In addition, then, to influencing plants directly, 
water affects them by changing the temperature and length 
of the growing-season. 

13. Sunlight. — Nearly every lawn with trees on it 
has weak sod and pale green grass in the shady spots. 
This is most marked under trees with dense foliage, such 
as low-growing evergreens. Lack of sunlight causes this 
injury. Plants vary as to their sunlight requirements, 
however, as they do in regard to heat and moisture. The 
best quality of celery and lettuce, and the finest tobacco 
leaves grow in half-shade. Orchard-grass is named from 
its fondness for shady spots. Rhubarb stems can be made 
long and tender, and asparagus stems white, by " blanch- 
ing " with boards or earth. Forest trees do not have low 
branches because lack of light kills the shaded limbs. 
The height, branching, and coarseness in flax and other 
crops are controlled by thickness of planting. 

Crops that store great quantities of starch or sugar, 
such as sugar-beets and potatoes, are benefited by clear 



TJie Plant and its Environment 19 

weather. Sunlight is essential to starch and sugar pro- 
duction. Therefore, in very rainy regions where the sky 
is overcast with clouds much of the time, sugar-beets, at 
least, do not thrive so well as they do in sunnier sections. 

14. Wind. — One reason why large trees must have 
strong trunks is that heavy wind§ exert enormous pressure 
on leafy tree-tops. Weak plants and even gigantic forest 
trees are broken down or uprooted in tornadoes. Vines 
and clinging plants lie close to the ground or cling to the 
branches of trees, or to walls. This prevents air currents 
from getting under or behind them. 

Sometimes strong wind shifts the surface soil so badly 
that roots of young plants are uncovered. Tender leaves, 
stems, or flowers may be rasped by the wind-borne sand 
grains. Plants with tough coverings, such as cacti and 
some grasses, suffer less. The formation of sod greatly 
aids the farmer in preventing this injury and in reducing 
that caused by contact with blown soil particles. Where 
hot, dry winds blow for several days continuoush', evapora- 
tion and transpiration are increased to such an extent 
that plants are " burned ". from sudden drying. Crops 
subjected to such winds present a dry, blasted appear- 
ance not far different from frost or fire injury. 

Winds are temperature regulators, for they mix the 
air, preventing cold or warm air from remaining in one 
place long enough to do injury. 

15. Soil. — Crops do not thrive in hard, dry soils 
impervious to water, air, and roots. Soils may be loose 
enough to blow readily, or sticky enough to " bake," or 
puddle, when wet. Soils that are shallow or underlaid 
with gravel are likely to dry out easily, thereby diminish- 
ing the supply of available moisture. The principal 
soil factors that influence plants are fertility, degth, ujii- 
formity, and water-holding power. Sometimes a plant 



20 



The Principles of Agronomy 




cannot get enough 
mineral food to 
enable it to grow ; 
abnormal arrange- 
ment or size of soil 
particles may pre- 
vent proper root 
development. As 
already pointed out, 
moderate moisture 
in the soil is more 
favorable than ex- 
treme wetness or 
dryness. Decayed 
leaves, stubble, and 
manure render soils 
capable of holding 
more water, thus 
insuring a steady, 
reliable supply. To 
create these desir- 
able conditions and 
to control weeds, 
insects, and plant 
diseases are the 
chief virtues of 
cultivation and 
manuring. 

16. Pests.— 
Great numbers of 
weeds hinder growth 
by shading, by steal- 
ing moisture and 
plant-food, and by 



The Plant and its Environment 21 

usurping room both in the ground and above it. Insects 
that eat leaves, flowers, roots, and stems of the growing 
plant or that suck sap not only retard development, but 
in some cases kill the crop entirely. Plant diseases which 
do likewise usually feed upon the sap preventing proper 
nourisliment. Smut of wheat or oats injures the quality 
of the grain or prevents its maturity. Potato diseases 
hinder the crop almost more than any other single factor. 
Control of these pests is at some time a problem in every 
locality. In Texas, for example, the cotton boll-weevil 
is driving cotton from some lands and compelling better 
culture methods everywhere. Fire-blight of pears has 
almost ruined the pear industry in much of the West. 
Attention to these negative factors may be as important 
as to the positive ones, for the farmer loses all the labor 
put on a crop which he cannot harvest. 

17. Adapted crops. — Only those crops that mature in 
the growing-season of any section are grown there to advan- 
tage. Some varieties will prove more thrifty than others. 
Grimm alfalfa thrives much farther north than ordinary 
varieties ; alsike clover resists much wetter soils than red 
clover ; and Turkey red wheat is adapted to dry climates. 

Finally, a variety of any plant long cultivated in a partic- 
ular section develops resistance to frost, water, heat, or 
drouth. Desirable strains may be started from single 
plants that have resisted some hardship more success- 
fully than other plants. This is only a part of the con- 
stant attempt of plants to adjust themselves to their 
surroundings. Environment has modified the plant and 
will continue to do so. Meantime, it gradually becomes 
better and better adapted to the section. This is the 
chief argument for home-grown seed. By this means, 
man lends a helping hand to the plant struggling to fit 
itself for its surrounding. 



22 The Principles of Agronomy 



SUPPLEMENTARY READING 

Any textbook of botany. 

Plant Physiology, B. M. Duggar, pp. 1-14, 400-435, and 494-507. 
Oncology of Plants, E. Warming. 
Plant Geography, A. F. W. Schimper. 
Plant Physiology and Ecology, F. E. Clements. 
Relation Between Climates and Crops, Cleveland Abbe, Weather 
Bureau Bulletin No. 36. 



CHAPTER III 
PLANT STRUCTURE 

Just as a locomotive engineer needs to know the parts 
and arrangement of his engine to keep it working smoothly, 
so the farmer must understand the mechanism and func- 
tion of plants in order to remove obstacles in the way of 
their best development. Plant structure determines 
in a large measure plant functions, and economic produc- 
tion depends on the unobstructed activity of life processes. 
Therefore, a clear understanding of the kind and loca- 
tion of activity that goes on within the plant will enable 
the farmer to handle his crop more satisfactorily. This 
is particularly true under abnormal conditions such as 
plant diseases, the nature and location of which must be 
understood for effective control. 

18. Cells (Fig. 4). — Roots, stems, leaves, bark, and 
flowers are so readily distinguished that everybody knows 
about them. Rings in wood, rind of melons, bran of 
wheat, and pith of corn are likewise matters of common 
observation. Neither pores in the skin of animals nor 
openings in the leaves of plants can be seen with the un- 
aided, eye, yet every wide-awake schoolboy knows of them. 

Under the microscope, not only the stomata of the 
leaves can be seen, but a vast number of minute parts 
which seem to be more or less independent of one another 
in that they are separated by walls of compact substance. 
In the outer bark of trees, nothing remains but the walls 

23 



24 



The Principles of Agronomy 



which seem to be built of a vast number of small, box-like 
structures. When cut across, they resemble to some 
extent the cells of a honey-comb. Because of this resem- 
blance, the name cell was chosen. 

Originally, " cell " was used to designate only the 
inclosed space within the box-like walls. Examination of 

living plants showed 
that neither the open- 
ing nor the wall was 
so important in the 
make-up of the plant 
as the mass of living 
substance occupying 
the inclosure. It was 
found that this liv- 
ing substance instead 
of being uniform was 
composed of several 
parts differing chiefly 
in compactness. 
Moreover, it was dis- 
covered that each cell 
took in food and oxy- 
gen independently of 
other cells ; that one 
cell might live or die 
without materially 
affecting others ; that 
growth consisted in an increase of the size and number 
of individual cells; and that when work is done, the 
cells do it. 

Since the cell is the primary consideration in the life 
processes of the plant, the substance composing it was 
named protoplasm from proio, meaning the first, and 




Fig. 4. — Plant cell showing ccll-wal), 
cytoplasm, nucleus, and vacuoles. (After 
Duggar.) 



Plant Structure 25 

plasma, meaning substance. As previously indicated, 
the cell is composed of several unlike parts. Beginning 
at the outside, there are (1) the compact protective wall 
known as the cell-wall ; (2) a membranous covering 
known as the plasma membrane which incloses the plastic 
cell-contents ; (3) a semi-transparent, semi-fluid substance 
something like the white of an egg known as the cytoplasm ; 
(4) a more concentrated part of the cytoplasm called the 
nucleus which refracts light and is stained by certain 
chemicals ; and (5) a number of smaller bodies known 
as plastids, of which there are three kinds : (1) green, 
(2) white, and (3) other colors, such as red, yellow, or 
brown. Seldom, if ever, does the protoplasm fill the 
entire cell. Every cell contains spaces interspersed within 
the cytoplasm known as v^acuoles. These sometimes 
contain solid substances, but they are usually filled with a 
solution of water and salts known as cell-sap. 

19. Tissues. — All parts of the animal or plant body 
are made up of cells. Skin consists of flattened cells 
with rather tough walls ; muscle is made up of fibrous 
cells that fit closely ; bone cells are heavily laden with 
mineral matter; and the brain is composed of layers of 
variously-shaped nerve cells, some white and others gray. 
A group of cells much alike and serving in a particular 
way is known as aPt issu e. 

The epidermis or peel of an apple, the flesh, the seed, 
the seed-coats, and the stem are plant tissues. Leaves, 
stems, roots, buds, flowers, and seeds are all composed of 
several tissues. It is by means of united cells specialized 
to some end that the plant performs its functions of 
taking in water, manufacturing starch or sugar, and stor- 
ing food. Tissues comprise the plant structure in much 
the same way that walls, plaster, floors, windows, and 
doors make up the house. 



26 The Principles of Agronomy 

■ 20. Kind of plant. — Only higher plants have well- 
developed tissues. The structure in one class of plants, 
the bacteria, consists of one cell or at most a few which 
are not grouped into tissues. Each cell performs all func- 
tions for itself. As the scale of plant life ascends, cells 
group themselves into more and more complex tissues 
until in seed plants each tissue or organ is highly specialized 
and performs only one function. 

Plants alike in all essential points are , said to belong 
to the same sj3ecies ; clo^elyTelated species belong in the 
same genus. Genera (plural of genus) that resemble 
each other comprise a family. Families in turn form 
orders, and these, sub-classes or classes. A final group- 
ing of classes gives rise to four great groups which make 
up the plant kingdom. Among the seed plants known as 
spermatophytes, all the crop plants occur. Thallophytes, 
bryophytes, and pteridophytes which are represented by 
seaweeds, mosses, and ferns, respectively, are the other 
great groups. Beginning with thallophytes and ending 
with spermatophytes, these plants show a gradually 
increasing complexity. There is no exact place where a 
species or genus, or even a group, ends with absolute cer- 
tainty. It is hard to tell whether certain organisms 
belong to the plant or to the animal kingdom. 

Though even botantists sometimes disagree in regard 
to the species to which some plants belong, these classes 
are sufficiently definite and the names are sufficiently well 
chosen to enable students of plants to identify them rather 
accurately by the names of the genus and the species. 
These Latin names are necessary because the same plant 
is popularly known by different names in different coun- 
tries, and even in different parts of the same country. 

21. Crop plants. — Plants in the same group or species 
are much like each other. The tissues of all seed plants 



Plant Structure 



27 



(spermatophytes) resemble each other enough to be de- 
scribed as a group. In method of growth, there are two 
kinds, monocotyledonous and dicotyledonous. Grasses 
are monocotyledonous, that is, they have undivided seeds. 
They grow largely by increase in size of cells ; dicotyledon- 
ous plants have split seeds and grow by laying down rings 
of new tissue. Practically all crops, save only the grasses 
and grains, grow by adding tissue in rings. Though dif- 
fering in growth habits and in appear- 
ance, they do work by similar means. 

22. Plant parts. — Crop plants 
have roots, stems, leaves, flowers, 
seeds, and buds which are simply 
leaves or flowers in protective cover- 
ings. The roots anchor the plant 
in the soil and take up water and 
mineral plant-food in solution. Stems 
hold the leaves and flower up into 
the sunlight, transport to the leaves 
the water and mineral salts, and 
carry elaborated food from the leaves 
to the roots. Some plants use them 
as a place in which to store food. 
This elaborated plant-food is manu- 
factured by the leaves in the pres- 
ence of sunlight, when moisture, 
carbon dioxide, and mineral salts 
are available. The flowers are fore- 
runners of the seed by which the 
plant transmits life and reproduces 
its kind. Each crop plant is composed of a number of 
tissues which enable it to perform its functions. 

23. The root (Figs. 5-7). — A careful examination 
with a microscope of a longitudinal section of a living 




Fig. 5. — Root-hairs 
on radish. (After 
Duggar.) 



28 



The Principles of Agronomy 



root shows the growing section to be a short distance 
behind the tip. The very tip is the root-cap composed of 
a group of firm cells which push aside the soil particles 
as the root lengthens. The tender growing cells could 
not make their way through the hard, compact soil. 

Just behind the growing area and still on the thread- 
like rootlets are the root-hairs. These are extremely 




Fig. 6. — Root-hair in the soil. 

small projections that radiate outward from the root to 
take in water and dissolved plant-food. The root-hairs 
are cells extending out from the small roots into the soil. 
They contain within a thin cell-wall, plasma membrane, 
cytoplasm, nucleus, plastids, and vacuoles. A concen- 
trated solution of numerous salts known as cell-sap fills 
the vaculoes. 

Considerable adjustability as to shape permits root- 
hairs to force themselves into close contact with soil 
particles and to fit into every space and around every angle. 



Plant Structure 



29 



Wherever contact with a soHd body is made, a mucilag- 
inous substance develops on the outside of the cell-wall 
causing it to cling tightly. Very close contact between the 
root-hairs and soil particles makes possible a rapid ab- 
sorption of film moisture and plant-food. 

Root-hairs may be half an inch long, though they are 
usually much less. They are short-lived, old ones dying 




Fig. 7. — Root-tip of corn. (After Curtis.) 

and new ones forming continually. As the root gets older, 
root-hairs cease to form and the epidermis takes on a 
nearly water-proof coat. Beneath this protective epi- 
dermis, various tissues form in layers. One of these, the 
xylem, takes up water and carries it toward the stem in 
small tubes known as tracheal tubes or in elongated cells 
known as tracheids. Between this water-transporting 
tissue and the epidermis lies the endodermis, a layer of 
cells rich in starch, and the cortex, a layer of corky cells. 



30 The Principles of Agronomy 

Water passes between these cells reaching the xylem, which 
lies partly inside and partly outside of the phloem in roots, 
though in stems the phloem is always outside. This 
alternating arrangement permits water to enter the tra- 
cheal tubes without passing through the phloem, which 
carries the true sap downward from the leaves. Water, 
after ascending the roots, passes into the stem, still going 
upward in the tubes of the xylem. 

All the roots and root-branches of a plant form a root- 
system. If the central root grows faster than the others, 
subordinating the side roots, the plant has a tap root- 
system, of which alfalfa, carrots, and red-root pigweeds 
are examples. In other plants, the side roots keep pace 
with, or outgrow the central roots giving rise to a fibrous 
root-system, such as those of grasses and cereals. 

24. The stem (Figs. 8-9). — The xylem of the stem, 
into which water passes from the root, connects with 
the xylem of roots afl'ording a somewhat continuous 
passage to the leaves. The tracheal tubes, by means of 
which this transfer from roots to leaves is effected, are 
minute tubes with thickened walls. In formation the 
end walls of cells directly above each other gradually 
dissolve out leaving a continuous opening sometimes 
an inch or more in length. The walls are thickened 
spirally or have pits in woody walls. This thickening 
stroigthens the stem, while the thin places permit a more 
ready passage of liquid into and out of the tubes. At 
the end, one tube does not connect directly with the next, 
but is slightly to one side making a lateral movement of 
water necessary. In this way, a straight lift is avoided. 

Examination of a xylem cross-section under a micro- 
scope shows the enlarged tracheal openings arranged in a 
row alternating with a row of more fine-grained wood tissue 
which supports the weaker tube area. These wood cells 



Plant Structure 



31 



Jail wccJ apriny tvccJ _ ^, , find (c/' ccF-tex) 

, ^t Sj, 




Fig. 8. 



Ys\fi 

-iast-^ rf'/irf (or cortex) 

lOA/e/T t/O/NAC ^cer/OJif 

-Section of oak branch showing longitudinal and cross-section 
tissues. (After Osterhout.) 



32 The Principles of Agronomy 

die leaving only heavy cell-walls. Just at the outer edge 
of the xylem is a layer of thin-walled cells that grow and 
divide leaving new tubes and new wood fiber on the inner, 
or xylem side ; while on the outer side it lays down a 
smaller quantity of less compact tissue known as the 
phloem. 

Xylem, phloem, and the growing layer, cambium, form 
what is known as the fibro-vascular bundles of the plant. 
These are small at first, but if the plant is perennial and 
completes a ring of new growth each year, they increase 
in size until they form a series of wedge-shaped bundles 
radiating from the central pith. Medullary rays pass 
radially between these bundles dividing them from each 
other. Along these medullary rays, food, air, and water 
move to deeper tissues. When bark is stripped from a 
willow, for example, it parts from the wood at the cam- 
bium exposing a smooth, moist surface. The rings of the 
woody part mark a division between the tubes and the 
finer, more compact wood cells ; the radial markings are 
medullary rays ; and the pith is a region of broken-down 
cells that originally composed the first stem of the plant. 

Several distinct layers come off in the bark. On the 
outside is a membranous tissue, the epidermis, which is 
composed of flattened cells with tough walls and which is 
covered with a substance that renders them water-proof. 
Beneath this is a region of thickened walls, and still farther 
beneath is an area of corky cells known as the cortex. 
Stone cells are scattered throughout this tissue. A layer 
of cells rich in starch, called the endodermis {endo, inner, 
and dermis, skin), divides the cortex from the pericycle. 
This last ring is composed of thin-walled cells and more or 
less regular areas of strong-walled, fibrous cells known as 
bast. Penally comes the phloem, which lies next the 
cambium and just in from the xylem. 



Plant Structure 



33 



Within the phloem is a series of cell passages, which are 
known as sieve tubes. These do not lie directly above 
each other, but slightly to one side. Down the sieve 
tubes flows the true sap, which is a solution of elaborated 
plant-food manufactured in the leaves from the water, 
gases, and mineral. This tissue extends into the roots, 
where, instead of lying outside the xylem, it alternates 
position with it, thus permitting water to enter the xylem 




Fig. 9. — Conducting cells of the fibro-vascular buncUes. (Adapted from 

Duggar.) 

without first passing through the phloem. In both root 
and stem, this sap leaves the phloem at intervals and 
diffuses outward in spaces between the cells and inward 
along the medullary rays. Old trees are mostly xylem 
with epidermis broken off, exposing the corky cortex. 
In most monocotyledonous plants the entire tissue is in 
a firm rind in the outer rim of the stem, which is usually 
jointed and hollow save at the joints, or nodes. Since 
no cambium exists, there can be no rings of growth. On 



34 The Principles of Agronomy 

this account, members of this group — grasses and palms 
— are usually slender for their height. In some, such as 
corn, the internodes are filled with pith interspersed with 
the strands of the fibro-vascular bundles. The stem is 
much harder at the nodes than at the internodes, and it is 
smaller in each successive internode that is farther from 
the ground. 

25. The leaf (Figs. 10-11). — Water-conducting tissue 
of the xylem joins the leaf-veins which distribute the 




Fig. 10. — Section of leaf showing cellular structure. 

water throughout the leaf, finally leaving it in the spaces 
between the cells. The cells absorb the water and also 
carbon dioxide taken in through the stomata, as the small 
openings in the epidermis of the leaf are called. 

The cross-section of a leaf shows a layer of flattened 
cells with stomata at intervals on both the upper and the 
lower epidermis. With most ordinary plants, the number 
is greater on the under side. On each side of the opening 
is a small cell so placed that when the leaf wilts, it falls 
across the opening partly closing it, and thus reduces the 
loss of water. Beneath the upper epidermis is a group of 
cells containing many green plastids. If the chlorophjdl 
cells are elongated vertically and lie side by side, as they 
often do, they are known as palisade cells. Below these 
cells lie others called sponge cells which are less closely 
knit together, thereby allowing more space between. 



Pkmt Structure 



35 



Just above an opening, the sponge cells spread apart 
leaving a larger chamber (Fig. 11). 

Leaf-veins may branch at the base as in grapes, or from 
a midrib as in alfalfa. In this case the veins form a sort 
of net-work called netted venation. This is typical of all 
dicotyledons. Grasses and grains are parallel-veined, 
that is, have the veins side by side either with or without 
a large central one known as the midrib. This kind of 
venation is typical of monocotyledons. 




Fig. 11. — Stomata of carnation leaf. (After Duggar.) 

Leaves may be borne on a leaf-stem, or petiole, or at- 
tached directly to the plant. They may be compound as 
with clover, alfalfa, and the potato, or simple as in the case 
of beans. The.y may be two-ranked as in the case of 
grasses and the grains. A leaf grows from a node, wraps 
closely about the stem for a distance, and spreads out- 
ward. The part that clasps about the stem is the leaf 
sheath, and the part that grows outward the leaf blade. 

26. The flower. — Seed production seems to be the 
prime purpose of all functions of the plant, which dies or 



36 



The Principles of Agronomy 



discontinues growth as soon as mature. The flower is 
the fore-runner of the seed, in that the seed is a product of 
a union of the floral parts. These floral parts are the 
corolla, calyx, stamens, and pistil. 
The corolla, the showy part of the 
flower, consists of petals, single or 
united, regular or irregular in shape 
and size, and usually of delicate tex- 
ture. The calyx is composed of 
firmer tissues, single or united, usu- 
ally regular in size and shape, and 
nearly always green. The calyx is 
an envelope for the remainder of the 
flower and the petals attract insects 
useful in cross-pollination. 

Each stamen consists of a slender 
stalk and a hollow receptacle bearing 
powdery pollen. There are from 
three to twenty or more stamens on 
a flower and they are situated inside 
the corolla, usually surrounding the 
pistil. The pistil consists of a rough- 
ened or divided stigma supported on 
a style that reaches upward from the 
ovule or ovary at the base (Fig. 12). 
When pollen grains reach the stigma 
they germinate and send long, slender 
tubes down the style to the ovule. 
Dissolving its way to the ovule, this 
tube comes in contact with the egg 
cell, which it fertilizes causing a seed to begin development. 
Flowers are borne singly or in clusters. If the cluster 
is a close, compact one, such as red or white clover, it is 
called a head. A cluster arranged like oats with long, 




Fig. 12. — Pistil of 
legume showing fer- 
tilization. 



Plant Structure 37 

slender branches connecting the separate flowers is called 
a panicle ; while one w ith the branches shortened to the 
extent that the flowers are in a compact, elongated mass 
is called a spike. Wheat, barley, and timothy are spikes. 

27. The seed. — As maturity approaches, the seed 
gradually assumes a characteristic shape, size, and ap- 
pearance. Some are smooth and nearly bare as alfalfa 
seed ; others, such as some grasses and barley, are covered 
with a hull ; still others are large and protected only by 
a membranous covering as with corn, peas, and beans. 

Within the seed is (1) an embryo, or germ, which is a 
miniature plant; and (2) a food supply to nourish the 
plantlet until it can gather nourishment. Some kind of 
covering or hull surrounds the seed protecting it from 
injury until germination time, when water is absorbed 
through the hull to start growth. 

28. Buds and branches. — Budding leaves and flowers 
must have some protection until they are strong enough 
to expose themselves to the weather, and until conditions 
favor growth. A series of scales coated with a resinous or 
gummy substance makes up this protective covering called 
a bud. Some buds are lined with soft, fluffy material to 
protect the tender leaves or flowers from cold wind, and to 
prevent excessive drying. 

Branches begin growth from a bud in the axil of a leaf. 
At first the union extends only to the cambium, but as 
rings of growth are added the branch is embedded in 
deeper tissue. Thus, knots are formed in timber. Just 
at the base of a branch the stem is usually enlarged. 

29. Underground stems. — Potatoes and onions are 
modifications of enlarged stems. They show the various 
tissues described, but lack much tissue that is composed 
of strong-walled stone, wood, or bast cells. Many grasses 
and weeds send rootstocks horizontally beneath the surface 



38 The Principles of Agronomy 

soil. These contain buds which will start both stems and 
roots of new plants. By this means, sod is formed and 
plants spread underground. 

Many plants, such as beets, carrots, alfalfa, and dande- 
lions, form root-crowns, which are closely united stem and 
root. Buds necessary to sending up new plants can 
develop only in stem parts. Root-crowns and rootstocks 
are simply modifications adapted to perform this function. 



SUPPLEMENTARY READING 

Any textbook of botany. 

Plant Anatomy, W. C. Stevens. 

Plant Physiology, B. M. Duggar, pp. 15-63. 

Cyclopedia of American Agriculture, Vol. II, pp. 11-22. 

Methods of Plant Histology, C. J. Chamberlain. 



CHAPTER IV 
PLANT FUNCTIONS 

Specialization in higher plants has given rise to a great 
number and variety of structural tissues. This difference 
presupposes different functions, that is, each tissue performs 
a definite kind of work. Moreover, it is highly probable 
that tissues slowly developed on account of the necessity 
of the work. In the struggle for existence, the individual 
plant with best-adapted means of doing essential work 
thrived best. Gradually plants with structures best 
fitted to carry on the activities have crowded out others. 
Since specialized work is more effective, plants more and 
more differentiated, have gradually been evolved. This 
seems to hav-e been much more true on land, where condi- 
tions varied more than they did in the ocean. The greater 
number of forces, such as light, soil texture, varying mois- 
ture, and temperature differences, naturally demanded 
greater complexity in response. This, in turn, required 
expression in a way conducive to the best good of the 
plant. 

30. Growth. — Though higher plants are complex at 
maturity, they have but few tissues just after germination. 
As growth proceeds, the original sprout develops into 
leaves, stem, and roots. Buds, branches, flowers, seed, 
and rootstocks or tubers come later. A rapid differentia- 
tion of tissues accompanies increase in size, and in some 
cases runs ahead of it. Many plants develop tracheal 

39 



40 The Principles of Agronomy 

tubes, sieve tubes, cambium, cortex, and epidermis while 
the phant is still small. 

Growth, whether measured by the increase in size or 
by the development of new tissues, can come only from 
enlargement, or increase in the number of cells. Each 
process is partly responsible. At first, the original cells 
increase in size, but soon they reach a point where little 
more growth results unless the cell divides. In all crop 
plants, both processes go on at the same time. 

Thin-walled cells in growing parts of a plant constantly 
divide and redivide forming new cells. The first sign of 
cell-division is in the nucleus, which begins to change from 
a granular to a fibrous mass. Shortly it seemg to be 
composed entirely of strands. These split lengthwise 
and then crosswise forming pairs of small bodies which 
arrange themselves in two parallel rows across the middle 
of the cell. Fine thread-like strands gradually pull these, 
half to one end, and half to the other end. Here they 
partly unite. The two move farther apart and become 
distinct. Following this, the cytoplasm begins to show 
signs of separation by developing a concentrated layer near 
the middle and between the two nuclei. When this has 
hardened into a cell-wall, cell-division is complete and two 
cells have come from the original one. In a few hours, 
or a few days, the two new cells may divide giving rise 
to more new cells, each behaving as the first so long as 
growth continues in that region of the plant. 

Young plants at first grow throughout, but soon dicoty- 
ledonous plants develop a cambium and growth discon- 
tinues in other parts except at the tip of elongating 
branches. All later thickening results from cambial 
growth. This ring of cells remains thin-walled and 
active, building first one side to the xylem and then on the 
other to the phloem. Just what determines which cell 



Plant Functions 41 

remains active in the cambium and which becomes per- 
manent tissue in the xylem or phloem is not understood. 
Early growth usually produces abundant tracheal tubes 
in order to get water to the leaves. This is followed by 
a ring of smaller, more compact cells for support. 

Monocotyledonous plants lack this power of secondary 
thickening, because they have no cambium. Cereals 
and grasses gain most of their thickness in early growth. 
Later increase in size is largely increase in length or 
storage of food in the seed or stem. 

31. Respiration. — Of the various needs of plants or 
animals, none requires more instant gratification than that 
of oxygen. A person can live days without food, hours 
without water, but only a few minutes without air. So 
it is with the plant. Fruit in storage not well ventilated 
soon suffers from storage scald. Alfalfa dies in water- 
logged soils largely because air cannot pass through the 
water to the roots. A layer of clayey sediment may 
cause the same result if it packs tightly. 

Although an abundance of air is at hand, it must reach 
the separate cells to be of service. Therefore, the oxygen 
must not only be in the soil or be in contact with the plant, 
but it must get inside the plant and circulate with sufficient 
freedom to carry a supply to living cells deep within the 
tissues. Some oxygen is taken into plants in water, some 
through pores or lenticels in the epidermis, but most 
through the stomata. Once inside, spaces between the 
cells afford channels of movement. Sometimes these 
intercellular spaces occupy more volimie than the cells. 
A plant-cutting thrust through a cork until the cut's end 
is under water gives off bubbles of air if there be another 
hole in the stopper to prevent pressure. This shows that 
air passes through the plant. 

Growth also requires oxygen. Seeds in air-tight vessels 



42 The Principles of Agronomy 

will cease to grow when the air is used up. A coat of oil 
over water containing seed greatly delays germination, 
because oxygen is unable to penetrate the oil. On the 
other hand, seeds germinate freely in water not so treated. 

Actual respiration takes place inside the cell which 
partly decomposes in doing work. Oxygen is necessary 
to the proper breaking down of cellular compounds. 
Food and water are also necessary to repair the wear. 
Cells are constantly losing weight as protoplasmic sub- 
stances become gas and pass off; they are likewise 
gaining weight as food is made into protoplasm. This 
exchange of worn-out protoplasm for food which becomes 
new body tissue is respiration. Carbon dioxide is excreted 
along with water and other products of slow combustion. 

Potatoes and apples soon wilt if kept in a light, fairly 
warm place, because of the loss of water and carbon 
dioxide due to respiration which increases much in rapidity 
as temperature and light increase. Again, if a plant be 
made to grow in distilled water in the dark, it also loses 
weight. In this case, the water supplies no food, and 
darkness prevents the plant from manufacturing any. 
Only respiration is active; it has used substance which 
through lack of food it is prevented from replacing. 

32. Photosjnithesis. — Ordinary plants growing in dark 
places do not gain in weight ; their leaves lack the char- 
acteristic green color of normal crop plants ; and the build- 
ing of tissue can go on only for a short time. Both sun- 
light and the green substance known as chlorophyll are 
essential to increase of dry weight. Young seedlings grow 
in darkness if other conditions are favorable, yet no 
increase takes place, for they move food from the seed 
storehouse to growing tissue. The quantity of food avail- 
able must last until the roots can supply water and mineral 
salts, and until leaves have reached into light and air 



Plant Functions 43 

and become green. Under favorable conditions the plant 
can then feed itself. 

Water, dissolved salts, and gases are taken in by the 
plant. From these raw food products it is able to make 
grain, straw, leaves, fruit, and roots composed of sugar, 
starch, cellulose, protein, fats, ash, and various other 
substances. Carbon dioxide, present in a very small 
percentage in the air, enters the leaves through the 
stomata. Diffusing in the spaces between the sponge and 
palisade cells, it comes in contact with water that is making 
its way in the opposite direction. Chlorophyll with the 
help of su nligh t unites water and carb on dj oxide into 
sugar. Considerable oxygen is liberated in this process — 
infinitely greater quantities than the plant uses in respira- 
tion. In consequence of this, oxygen is given off by the 
plant. This oxygen comes not from the breathing of 
the plant, but from the manufacture of food in the leaves 
which is called photosynthesis (from ijhoto, light, and from 
synthesis, to put together). Chlorophyll, in an unknown 
way, accomplishes this manufacture of plant-food after 
which the plant nourishes itself. The following chemical 
reaction shows the different beginning and end products : 

60)2 + 6 H2O = CeHisOe + 6 O2. 

Sugar, under the action of certain chemical ferments, 
called enzymes, changes to starch and this to oil or cellu- 
lose, and in some plants, to wood. But nitrogen, calcium, 
potassium, phosphorus, sulfur, iron, and magnesium are 
brought from the soil. Nitrogen and sulfur together with 
a little phosphorus are united into another class of com- 
pounds called proteins, a general term for any organic 
product containing nitrogen. 

Such is the way in which plants manufacture the raw 
inorganic elements into products they can use. All these 



44 



The Principles of Agronomy 



compounds find use in various parts of the plant. This 
union of raw elements into usable compounds is essential 
to the existence of all life. 

33. Osmosis. — For a long time it was known that 
water and nourishment are taken from the soil by plants, 
yet no clear understanding existed as to how they enter 
or what part they take in plant growth. Some thought 
the plant feeds entirely on water, and 
others that soil particles, as such, 
enter the plant. Jethro Tull, about 
1674, advocated that intertillage be 
practiced to fine the soil in order that 
it might enter the plant. Just how 
he expected this entrance to be made 
is not clear. Soon came discoveries 
showing that neither water nor soil 
alone is plant-food, but that certain soil 
elements, water, and carbon dioxide are 
united by photosynthesis to form the 
materials out of which plants build 
their tissues. The intake of carbon by 
leaves was established ; the entrance 
of water with mineral salts in solution 
by osmosis was proved. Knowledge 
of these basic principles enabled the 
science of plant production to advance with hitherto 
unknown rapidity. 

Kernels of grain, germinated on wet cloth or paper over 
a box of wet sand or sawdust, develop root-hairs for the 
absorption of water and mineral food. The seedlings 
will grow and use water, as will a geranium cutting passed 
through a stopper with the cut end under water. Roots 
will develop, the plant will continue to grow, and the 
quantity of water in the bottle will diminish though open- 




FiG. 13. — Apparatus 
used to demonstrate 
osmosis. (From 

Bailey.) 



Plant Functions 45 

ings around the stopper and plant be sealed to prevent 
evaporation. Since there was no other way of escape 
for the water, it must have been taken into the plant and 
passed upward through the stem. The process by which 
the plant accomplishes osmosis is complex. Liquids 
and gases — even solids in some cases — are driven 
through membranes or caused to diffuse into one another 
by a gigantic force spoken of as osmotic pressure. 

When copper sulfate (blue vitriol) crystals are covered 
with water, solution begins and a blue color gradually 
creeps throughout the water until a uniform color exists. 
Samples taken from any part of the vessel would show 
nearly equal concentrations of copper sulfate, which, at 
the beginning of the experiment, was confined to the 
immediate vicinity of the immersed crystals. This 
diffusion, or mixing of the salt throughout the water, 
was impelled by the p ower of diffusion or osmotic pressure. 

If the vessel containing water be divided by a partition 
of parchment or piece of animal bladder, a change in the 
final result is apparent. After awhile the water on one 
side of the membrane rises and lowers on the other. 
Since the membrane admits the free passage of water 
but not of salt, fresh water is driven through in an attempt 
to make the liquid of uniform concentration. Some salt 
passes through into the fresh water, but the chief move- 
ment is made by the water. 

To demonstrate osmosis, a strong solution of common 
salt may be placed in a thistle tube, over the large end of 
which a piece of parchment paper or bladder is tied tightly 
to shut out air (Fig. 13). If the solution stands high 
enough to reach into the small tube above the bulb, a piece 
of string or an elastic band can be used to mark the height. 
After immersion in fresh water from a few minutes to a 
few hours, the solution rises in the tube showing the intake 



46 The Principles of Agronomy 

of water. Osmosis, agriculturally, is the process by 
which water from the dilute solution flows through a 
semi-permeable membrane into the more concentrated, 
in an attempt to equalize the strength of the solution. 

It is by osmosis and due to osmotic pressure that roots 
take in water. Root-hairs contain concentrated solutions 
in the cell-sap which set up a difference in osmotic pressure 
between the cell and the water outside. Students of 
physical chemistry have found that this pressure is enor- 
mous, amounting in many cases to tons, and that it in- 
creases as the difference in solution-concentrations in- 
creases, and as the temperature rises. So long as the 
cell-sap is more concentrated than the soil solution, water 
passes inward. If strong solutions are brought in contact 
with the root-hairs, osmosis ceases or goes in the opposite 
direction and the cells become flabby and wilt. This 
is one injury caused by strong alkali. 

Plants seem able to exercise a power of selective absorp- 
tion ; that is, if salts are not used by the plant, they enter 
only in small quantities ; while the useful elements go in 
rather freely. This careful adjustment helps to keep out 
harmful substances and to take in the raw mineral plant- 
foods. Plant cells full of water are rigid and hold their 
shape. As one loses water, osmotic pressure causes more 
to enter. Throughout the plant there is some move- 
ment of water due to osmosis. 

34. Transpiration. — Not only do roots take in water 
enough to maintain the plant in a rigid condition, but 
they must, in addition, maintain a stream that passes 
entirely through the plant. Because the water evaporated 
from the leaves is in the form of vapor, it cannot be seen 
under ordinary conditions. On cool mornings, however, 
droplets of moisture are often visible on the surface of 
leaves. Water vapor, escaping by means of the stomata, 



Plant Functions 



47 



partly condenses when cooler air is reached. Even on 
hot days, in living or school rooms, transpiration — as 
this giving off of water is called — can be demonstrated 
by covering a leafy house-plant such as a geranium with a 
clean glass jar or open- 
mouthed bottle. In 
two or three hours the 
transpired water will 
collect on the glass in 
drops, and under favor- 
able conditions with a 
healthy plant will drip 
down the sides. 

Plants transpire enor- 
mous quantities. For 
each pound of dry sub- 
stance they add to their 
weight by growth, over 
200 pounds of water 
have passed through 
the plant. Measure- 
ments of transpiration 
show that about 300 
pounds of water are 
required for one pound 
of growth in corn and 
about 500 pounds for 
one pound of growth in 
wheat (Fig. 14). A pint of wheat weighs a pound, but 60 
gallons of water are necessary to produce it. If the straw 
weighs as much as the grain, three 40-gallon barrels full of 
water are transpired in growing the pint of wheat. This 
quantity of water used in growing a pound of dry substance 
is called the water-cost of dry matter for the particular plant. 




Fig. 14. — Comparison of water used with 
wheat produced. (After Widtsoe.) 



48 The Principles of Agronomy 

Crops growing in hot, sunshiny regions transpire more 
water than in humid regions. Dry air, winds, poor soil, 
weak plants, and an abundance of water in the soil cause 
more water to be used for dry matter produced. Desert 
plants and drouth-resistant crops have the power to hold 
so much water in their tissues against the forces of tran- 
spiration that they do not die from wilting. Some plants 
also have the power of developing few or many stomata 
according to whether they have small or large quantities 
of water at their disposal. Some plants transpire much 
more water than others ; most plants seem to be wasteful 
during the period of bloom ; and quick-growing crops use 
more water than steady-growing ones. Darkness also 
diminishes transpiration considerably. 

35. Translocation. — Since all the starch and other 
plant-food is elaborated in the leaves, this must be moved 
or the leaves would be the largest part of the plant. En- 
zymes change sugar into starch for storage, and then to 
sugar again when moving is begun. The solubility of 
sugar allows the sap stream to carry it to the fruit, stem, 
or root for use or for storage. For example, great quan- 
tities of sugar or starch are stored in roots of carrots to 
be moved to the flowers and seed when the plant matures 
and seed is set. Fruit trees move food from wood to the 
fruit. Seed and fruit often grow so rapidly that storage 
in early summer is necessary. This movement of elabo- 
rated food from one part of the plant to another is called 
translocation. Most crop plants become more or less 
porous in stem or roots, or in both, during the seed-setting 
period owing to the transfer of food material. 

36. Transportation. — Water is transported upward 
through the tracheal tubes and sap, downward through 
the sieve tubes, or radially along medullary rays. Sap 
can flow down largely by gravity and radially by capil- 



Plant Functions 49 

larity, or wick action. Both these forces aid osmotic 
pressure in forcing the water upward. Wliatever factors 
are at work, the water seems to have httle more trouble 
in reaching leaves on a tree-top 200 feet above ground 
than those on a strawberry plant. 

A geraniiuu-cutting with the cut end immersed in 
red ink will soon show red stains moving upward. They 
will finally extend along the leaf-veins causing red blotches 
in the leaves where the liquid is released into the spaces 
between the cells. A plant stem several inches in length 
will be traversed in a few minutes. The rate of movement 
varies from a few inches to several feet an hour. 

37. Response. — Nearly all plants tend to grow verti- 
cally, even on a steep hillside where it would seem that 
growth at right angles to the slope would afford the 
firmest root attacluuent. Most plants in windows lean 
toward the light, and must be turned every few days 
to prevent their becoming one-sided. Roots, in wet soils, 
nearly always grow in the surface layer, while on dry, 
well-drained soUs, they penetrate deeply. It is coimted 
a good practice to withhold irrigation water as long as 
possible in order to promote deep rooting. Oxygen as well 
as water limits the growth in swamped soils. Many 
plants do not thrive save on soils rich in lime. Alfalfa 
is a notable example. 

SUPPLEMENTARY READING 

Any textbook of botany. 

Plant Physiology, B. M. Duggar. 

Plant Physiology, L. Jost. 

Plant Physiology, G. J. Peirce. 

Cyclopedia of American Agriculture, Vol. II, pp. 11-22. 



CHAPTER V 
THE PLANT AS A FACTORY 

Notwithstanding their complexity, plants are simple 
in their purpose if they can be said to have such. All their 
energies are bent toward seed production or toward some 
other means of continuing the species, that is, of transmit- 
ting life and characteristics to another generation. Sin- 
gleness of aim seems to show the organization of the plant 
and the variety of ways in which it attempts to preserve 
itself in the struggle for existence. Power to gather 
raw foods and elaborate them into tissue-building com- 
pounds, storage of these products in some part of the 
plant against the time of greater needs, and adjustment 
to surroundings are nothing more than manifestations 
of the struggle to perpetuate the species. 

In the products of the plant, man is vitally interested. 
Sometimes it is the roots, sometimes the stem, the seed, 
or the fruit containing stored starch, sugar, oil, or pro- 
tein that draws his energy in producing and harvesting. 
Often it is just tlie dead cell-walls, such as wood, cork, or 
straw ; but other times he takes the plant in the midst 
of life to get immature stems for forage, sap for rubber or 
turpentine, or cell-contents for sugar. Every part of the 
plant has been put to use ; roots, stems, leaves, flowers, 
seeds, and sap, all furnish useful products. For example, 
beets and carrots are roots, hay is both stem and leaf, 
grain and beans are seeds, some perfumery is made of 
blossoms, and cane-sugar is a sap product. Drugs and 

50 



The Plant as a Factory 51 

stimulants, such as opium, tobacco, and quinine, come 
from substances known as alkaloids that may be found in 
any part. 

38. Interdependence of plants and animals. — If only 
plants were upon the earth, then the p^o^'ision of nature 
for plants to give up oxygen and use carbon dioxide and 
for animals to reverse these processes, would be useless. 
Animals feed upon plants, directly and indirectly ; directly 
when they are plant-eaters, and indirectly when they are 
flesh-eaters; for the prey of carnivorous animals either 
ate plants, or animals that ate plants. On the other 
hand, decayed bones, flesh, and manure restore to the 
soil and air substances upon which the plants feed either 
directly or indirectly ; directly when plant-food is at once 
taken from the broken-down tissues, and indirectly when 
these decaying substances promote the growth of soil bac- 
teria which take atmospheric nitrogen and make compounds 
that the plant absorbs. Soil devoid of organic matter — 
decaying plant and animal substance — is almost useless 
on account of its being compact. It can hold water 
for only a short tune ; air and heat cannot pass through 
it readily. 

Many plants require limestone soils for development. 
Part of the limestone ledges supplying lime is composed 
largely of shells of small animals that extracted lime from 
the water in which they lived. These animals probably 
fed on water plants, and breathed oxygen released as 
by plant processes. In the economy of nature, plants 
and animals need each other. 

39. Dependence of man on plants. — Since animals 
depend on plants for their food, man, who in turn depends 
on plants and animals, may be regarded as being ulti- 
mately dependent on plants. It is not difficult to see 
that almost all human food, save only a few minerals 



52 The Principles of Ayroiioniy 

siicli iis salt, comes (Mitircly iis a result of life ])r()eesses. 
Milk, cheese, hiitter, flesli, juhI v^f^^ are body products 
of auiinals; bread, fruit, vegetables, and "greens" 
are j)laiit contributions, l^'urtlierniore, they are ])roduee(l 
almost entirely by domesticated plants and animals. 

Clothing-, likewise, comes largely from the same sources. 
Cloth made from wool, hair, cotton, or flax fiber is just 
as truly the j)roduct of animals and ])laiits as are the skin 
garments of the P'skimo or the leaf and bark raiment of 
the tropical saAagc ; furs, gloves, shoes, and straw hats 
are made directly from products of the life processes. 

lA)rmcrIy, most dwelling places were built of wood and 
leaAcs or of skins. Modern buildings consist largely of 
brick, stone, concrete, and metal, but wood is used in 
lathing, for doors, door and window frames, for roofing, and 
for walls in many cas(>s. Furniture and useful tools will 
for years to come, if not always, be composed largely of 
wood. Attention to fonvstry indicates that man realizes 
this and is making an c^d'ort to })reserve his timber re- 
sources. l\I()rco\(T, far back in the liistory of cement, 
briek-elay, some rock, and some metals, life has played 
a, part. Kspecia,ll\' is this true where^'er carbonate com- 
])oun(ls exist, since others as well as Ihnestone have re- 
sulted from an organic process somewhere in the chain of 
interaction of the elements. 

The carbon dioxide used in ])li()tosyntliesis was the 
original source not onl>' of all carbonate products, but of 
all substaiic(>s such as wood, coal, ])etroleum, and natural 
gas. Combustion of these materials yields heat energy 
used to warm dwelling and office, to furnish power for 
dri\ing the (Migincs of factory an<l transportation, and to 
generate electricity for both, i)ower and light. 

Animals themselves are direct bearers of burdens and 
drawers of loads. Horses i)ull tillage imi)lements and 



The Plant as a Factory 53 

haul farm products to market ; camels, llamas, and 
burros carry man and goods in regions inaccessible to 
wagon and locomotive. Horses and dogs assist in tend- 
ing herds ; cats and birds in the control of mice and in- 
sects ; bees and other flying folk pollinate flowers. Not 
only are the labors of man lessened by dumb beasts that 
live on j)lants, })ut his i)leasure is also increased })y them. 
Riding and driving are healthful recreations ; ponies, 
dogs, and birds gladden the hearts of children who have 
them for pets ; zoological gardens and aquariums are 
places of beauty; and caring for and breeding fancy 
animals are avocations of many. 1^'lower gardens and 
house plants also beautify the home. Vegetable gardens 
and ornamental plants satisfy some men in the same 
way that good animals do others. 

Many raw products that are transformed by factories 
into new forms, whether food, clothijig, tools, or books, 
are of plant or animal origin. Books, pictures, and news- 
papers, so essential in education and in national and 
artistic well-being, are made of paper or ch^th, both plant 
products. Medicines, dyes, and chemicals are supplied 
in part by plants. Finally, more people earn their living 
by the culture of plants and the rearing of anin)als than 
by any other pursuit, l^lainly, man cannot live in and 
of himself ; he must be fed, clothed, wanned, and sheltered 
from the weather. Since he cannot dispense with plants, 
let him not scorn them. 

40. Domestication. — When the people who are now 
civilized were savages, they lived much as present-<lay 
savages do. Wild fruits, nuts, roots, and tender shoots 
fed, clothed, and sheltered them. In the wild, enemies 
were frequent and they often prevented man's obtaining 
food. Rigorous winters and dry summers also caused 
suffering to some, while those in better provided areas 



54 The Principles of Agronomy 

were less disturbed. Stern necessity drove man to do- 
mesticate plants for food and shelter, and animals as 
assistants in hunting and in moving about. Originally, 
all tame creatures came from native haunts. If they 
were useful, the most savage brutes were gradually 
brought under subjection by man who alone could use 
fire and make machines to throw arrows or stones. Weaker 
than many animals and plants, he studied their ways 
and found ways of subjecting the useful ones. Seed was 
planted in protected places and other plants were kept 
out. Then tillage began and man took up a fixed habi- 
tation. 

Some plants and animals have been so long cultivated 
that wild relatives have disappeared. The earliest 
records tell us that wheat, barley, and alfalfa were culti- 
vated at the dawn of civilization. "Constantly new plants 
are being used for crops. In the cases of plants recently 
domesticated, the wild ' relatives are still in the fields. 
Wild plums and roses, native grasses, and vetches may 
still be found, but the plants from which wheat and corn 
came have disappeared. Plants not yet known could 
doubtless be found that would serve man, and as new 
varieties appear, many useful plants will be developed. 

41. Plant compounds. — Hundreds of kinds of sub- 
stances are found in plants. Some of these man finds use- 
ful and appropriates for his own use. So closely related 
are these compounds that they may be included in eight 
groups : (1) water, (2) carbohydrates, (3) proteins, (4) 
ash, (5) fats and oils, (6) aromatic substances, (7) medic- 
inal properties, and (8) acids. In importance the last 
three rank far below the first five, yet even these are not 
to be neglected. 

42. Flavors, perfumes, and other characteristic odors, 
such as lemon, mint, and rose-water, have various uses. 



The Plant as a Factory 55 

Flavors of fruit and nuts serve to distinguish them. 
Carbon, hydrogen, and oxygen in various quantities 
and arrangement compose these substances. The drugs 
and stimulants, such as morphine, strychnine, and quinine, 
usually contain nitrogen in addition; while the acids of 
fruits, such as malic acid in apples and tomatoes, citric 
acid in citrus-fruits and currants, and tartaric acid in 
grapes, consist of carbon, hydrogen, and oxygen. These 
three classes of compounds promote palatability, give 
variety, increase healthfulness, or stimulate the nervous 
system rather than serve as constructive foods. 

43. Water composes from 60 to 90 per cent of the 
weight of green plants. (1) It forms a part of the cell 
content keeping the cells full and rigid ; (2) it acts as a 
solvent which carries mineral salts and distributes elab- 
orated plant-foods ; (3) it regulates the temperature of 
plants by maintaining a constant stream from root to 
leaf where evaporation, which uses much heat, reduces 
the temperature to normal. In the animal body, water 
performs similar functions. The extra succulence caused 
by water in plant tissues increases palatability. Dry 
feed and water seem to lack something that green feeds 
possess, particularly for the use of milch cows. 

44. Carbohydrates consist of carbon, hydrogen, and 
oxygen usually in the ratio Cx(H20)j,. They comprise 
from 80 to 95 per cent of the dry weight of plants and are 
made from water and carbon dioxide. Starch, sugar, and 
cellulose occur in the plant, scattered widely throughout 
the tissues. Cellulose makes up all woody tissue and the 
strong cell-walls. Starch is the usual form of storage, 
while sugar is ordinarily the temporary form, though in 
sugar-cane and sugar-beets it is one of the storage com- 
pounds. When carbohydrates are digested by man and 
beast, they supply work and heat energy and may be 



56 The Principles of Agronomy 

made into fat. Never, however, do they become a part 
of the muscle, Hgaments, and connective tissue. Slow 
combustion in the cells uses these foods. Starch and 
sugars are easily digested, but cellulose, often designated 
as crude fiber, is but partly digested. However, it fur- 
nishes bulk, which is necessary. 

45. Protein compounds contain nitrogen and sulfur 
and sometimes phosphorus. Out of these foods, muscu- 
lar, connective, and vital tissues of the body are formed. 
Flesh, stomach, intestines, lungs, nerves, and brain use 
these in direct composition. Man eats meat to supply 
these needs because plants are not usually rich in nitrog- 
enous substance. Animal bodies must first get them 
from plants w^hich contain them in storage. Leaves, 
embryo of seeds, and a layer of cells just beneath the seed- 
coat are rich in nitrogen. Leguminous plants are much 
richer in protein than grasses or cereals ; and legiune seed, 
such as peas and beans, are composed largely of protein 
compounds. Proteins, then, are both scarce and vital ; 
they cost about three times as much as carbohydrates if 
ordinary prices are considered. 

46. Ash comprises from a fraction of one to several, 
but usually less than 2 per cent, of the dry matter. It 
is scattered through the plant as stone cells of the stem 
and leaf, in the cell-sap to promote osmosis, and in the 
protoplasm itself. A small quantity enters into the 
composition of protein. It is called ash because it re- 
mains so after burning. Animals concentrate this min- 
eral, in the bones and teeth, and use it in smaller propor- 
tions in blood and flesh. 

47. Fats and oils are simply carbohydrates rich in 
carbon and poor in hydrogen and oxygen. Seed embryos 
and the flesh of nuts are the storage tissues. All grains 
contain some : corn about 5 per cent ; seed of flax, sun- 



The Plant as a Factory 57 

flowers, cotton, mustard, rape, and poppies are about 
one-third oil ; peanuts, palm-nuts, and coconuts con- 
tain from 45 to 67 per cent. Fats and oils, in the animal 
body, produce fat and supply energy. In computing 
rations for live-stock, they are counted 2.4 times as valu- 
able for energy production as sugar and starch. 

48. The plant factory. — Since plants and animals use 
the same foods, and since the animal is not able to com- 
pound its own, the animal draws its food from the plant. 
True, the elements are the same and in the same quantity 
before and after photosynthesis, but they are in entirely 
different relations. Iron made into pig-iron and then 
into watch springs is the same substance in different 
forms ; but just as the watch-maker could make no use 
of the pig-iron, so the animal — and the plant for that 
matter — can make no use of carbon dioxide, potassium, 
nitrogen, phosphorus, or iron until they have passed 
through the factory of the leaf and been made over into 
sugar, starch, protein, or oil. Water alone is used in 
the compound that exists in nature. 

As described in paragraph 32, carbon dioxide and water 
are united into sugar by the chlorophyll of the leaf. This 
green substance is found throughout the green part of 
the plant, but it is abundant in the palisade cells of the 
leaf. Small green bodies arranged along the side walls 
of these cells intercept rays of sunlight and make use of 
this energy to do the work of combining water and carbon 
dioxide. The water within the cell touches the chlorophyll 
bodies on one side, while the carbon dioxide comes into 
intimate contact with them on the other, as it diffuses 
against and through the cell-walls from the stomata. 
Chlorophyll, by means of energy in the sunlight, causes 
this chemical combination to take place. Plants make 
no outward demonstration, yet, in quietness, they have 



58 



The Principles of Agronomy 



caused the most important reaction known. This is 
the beginning of the food which feeds all. The whole 
problem of feeding the world must ultimately be solved 
by chlorophyll and sunshine. Figure 15 represents appa- 
ratus showing aeration of the leaf. 




Fig. 15. — Apparatus showing aeration of the leaf. (After Detmer.) 

Without green plants, it would be simply a matter 
of time until life could not exist on earth. First plants 
would die and animals would feed upon them. Grad- 
ually these would use up the food and then die. Equally 
essential is sunshine, which not only enables plants to grow, 
but vaporizes water, lifting it into clouds which return 



The Plant as a Factory 59 

the water as rain, letting it run down hillside and hollow. 
In this journey, it washes soil and grinds rock, it floods 
meadows and turns water-wheels, it grinds grain and saws 
lumber, it dissolves mineral for plants and generates 
electricity. Sunshine, then, is the source of water power 
as well as the original power of warmth and food. In this 
whole world, only chlorophyll is able to make use of it 
for food manufacture. 

Just what this strange substance is, has not yet been 
found out. Plants growing in the shade continuously 
have none, l)ut as soon as they are exposed to sunshine, 
it develops. Sunshine and the living cell can bring this 
vital substance into action and perhaps into being. Truly 
the plant is a factory : sunshine furnishes the power to do 
work ; chlorophyll seems to be the machinery ; and water, 
dissoh'ed salts, and carbon dioxide are the raw products. 

49. Animal concentration. — Proteins occur only in 
small percentages in plant tissue. When the plant is 
eaten and digested, carbohydrates and oils are " burned " 
in doing work and the refuse excreted. Water is the 
same in plant, animal, and stream. Some ash is used, 
but save in young animals, it is mostly discarded in the 
manure. Protein is also partly excreted when fed in 
abundance, but part of it is retained and made into flesh, 
blood, and sinew. The animal has gradually accumulated 
a body composed largely of the vital tissue. When it is 
butchered, man gets a concentrated food which began in 
the plant cell, but which was refined in the plant and in 
the animal, and when cooked is adapted to his use. Brain 
and brawn, which have so changed the world, must look 
far back to find the beginning of their working power and 
of their tissues. 

50. Storage. — Man and other animals must do some- 
thing besides eat; hence they eat a quantity and gain 



60 The Principles of Agronomy 

reserve energy to carry them till the next meal. Should 
the following meal and still others be omitted, they live 
on stored food. Finally, fat and muscle waste away and 
starvation results. 

Something quite similar to this occurs in the plant when 
storage is made. During the fruiting period, plants use 
food more rapidly than they manufacture it. Perhaps 
it would be more accurate to say that the plant moves 
the food, or part of it, to the seed from the stem, root, 
or leaf. In annuals and biennials, the seed gets most 
of the food, while in perennials, it gets only part. The 
method of storage is almost identical whether in the 
seed, root, or stem. 

When sugar is first made it changes into starch. At 
night, starch can usually be found in healthy leaves, but 
usually not early next morning. Enzymes have changed 
it to sugar and the plant has transported it to the place 
of storage. Here it is again changed by enzymes into 
starch which now fills the white plastids of the cell just 
as chlorphyll did tlie green. A microscope shows this 
starch to be in rings with the center of formation on one 
side in the potato, and in the middle in beans. Plastid 
after plastid may be laden until the whole cell seems to be 
composed of starch. Here it remains until transloca- 
tion to the seed begins, when enzymes turn it to sugar and 
the plant carries it upward through the tracheal tubes. 

Proteins are deposited in the cytoplasm as crystals or 
globules, or as both. Less storing is done than in the 
case of starch, but it is handled in nearly the same way. 
Fats and oils usually enmesh themselves in the cytoplasm. 
Much seed storage is in the form of oil since most energy 
can be so stored in a given space. Embryos are rich in 
oil, supposedly on this account. 

Plants that store sugar deposit it as false crystals in the 



J 



The Plant as a Factory 61 

vacuoles when the cell-sap dries, leaving the sugar too 
concentrated to remain dissolved. Less soluble sugars 
are found in storage than in the sap of the same plant. 
This is natural, since insoluble starch and cellulose, and 
slightly soluble saccharose (cane sugar) are much less 
easily disturbed than the highly-soluble glucose (grape 
sugar) of the sap. 

51. Harvest. — Plants vary in composition as age 
advances because nitrogen and ash are taken up early 
and carbohydrates are manufactured later. The place 
of storage changes, leaving a plant part rich in food at 
one time and almost devoid of it at another. Man must 
know for what he wishes the plant. He must also know 
what part he wishes to harvest and when he will find what 
he wants in that part. Wheat makes the best hay at 
bloom or in the soft dough, but is useless for grain until 
nearly mature. Beets and carrots yield roots at the end 
of the first year, but seed only at the end of the second. 
It is rather general for stems, roots, and leaves to lose food 
material rapidly as the seed forms. 

If hay is the crop, let the grass or legume be cut when 
the leaves and stems are rich in delicious, digestible food. 
They must be cured in such a way as not to lose value by 
leaching with rain or by shattering. When seed is desired, 
the plants advance to maturity. Care that seed does 
not shell out is all that is necessary. If roots are required, 
biennials are harvested the first autumn ; if seed, then 
the tops are cut the second. Fruit is picked when full 
grown and mature enough to be delicious, yet when firm 
enough to withstand handling. Cotton is picked after 
the bolls break, but before the lint weathers from the seed. 

Man cuts short the life of the plant when it is in the 
condition that will best fit his purpose. Curing begins 
at once and goes on in sunshine or shade, hastily or gradu- 



62 TJie Principles of Agronomy 

ally, by air or by heat according to the product expected. 
Considerable knowledge of plants and effects of treat- 
ment are required. He who does this work must know 
his ground and work with precision. 

52. Control of the harvest. — As civilization has ad- 
vanced, man has gained more and more control over na- 
ture. More and better machines, propelled more effec- 
tively, have given him an enormous power to harvest 
large fields within a short time. Orchard-grass must be 
cut within a few days of bloom ; timothy may be mown 
any time within two or three weeks. American farmers 
have chosen to grow timothy. This enables them to tend 
much larger hayfields. Some wheats shell more easily 
than others ; some potato varieties ripen earlier than 
others ; and alfalfa is richer in protein than grass. All 
these factors enable man to control the harvest by choosing 
his crop wisely. 

Better cultivation, more thorough manuring, and wiser 
irrigation produce greater yields. The Utah Station 
found that the time of application and the quantities of 
irrigation water affected the proportion of stem, leaves, and 
grain, and also the chemical composition of these parts. 
It was found that moderate irrigation produced better 
qualities of grain, potatoes, and fruit than did excessive 
water which promoted woodiness and stem development. 

Thick planting yields slender, straight flax stems bear- 
ing long fiber but little seed ; thin planting, which allows 
branching, begets short fiber but much seed. Pruning 
may direct food from small useless growth to fruit, and 
thinning gives fewer but larger fruits. 

If man will but learn the ways of his crop, he may have 
largely within his grasp the power to get what he desires 
from the plant world. He may set certain forces in 
action ; and then, at the right moment, gather a harvest 



The Plant as a Factory 63 

superior in yield and quality to that of his less diligent 
neighbors. The Bible says : 

" And God blessed them and God said unto them, Be 
fruitful, and multiply, and replenish the earth, and sub- 
due it ; and have dominion over the fish of the sea, and 
over the fowl of the air, and over every living thing that 
moveth upon the earth. 

" And God said. Behold, I have given you every herb 
bearing seed, which is upon the face of the earth, and ev' ery 
tree, in which is the fruit of a tree yielding seed ; to you 
it shall be for meat" (Genesis i. 28, 29). 



REFERENCES ON PART I 

Any textbook of botany. 

Plant Physiology, B. M. Duggar, pp. 250-279. 

Chemistry of Agriculture, C. W. Stoddart, pp. 50-106. 

Plant Physiology, L. Jost, pp. 102-190. 

Chemistry of Plant and Animal Life, Harry Snyder, pp. 175-234. 

Principles of Irrigation Practice, J. A. Widtsoe, pp. 216-230. 



PART II 
THE SOIL 



CHAPTER VI 
WHAT THE SOIL IS 

The soil is not only the foundation of agriculture, 
but it is also the basis of all human prosperity. It is 
the most common, and yet the most precious, thing in 
the world. The fact that this productive blanket covers 
practically the entire land area of the globe makes it 
possible for man to get a living almost anywhere ; but 
in places where the soil is scanty the dwellings of man are 
few. 

53. Definition. — The soil is the loose material of the 
earth's crust in which plants find a home for their roots 
and from which they are able to secure certain foods neces- 
sary for their growth. Almost the entire land surface 
of the earth is covered with a layer of soil, which varies 
in thickness from a few inches to hundreds of feet, and 
in nature from fragments of rock on which weathering 
has scarcely begun, to muck soil composed almost en- 
tirely of organic matter. 

Some soils are rich in all the foods required by plants; 
some are rich in certain elements but deficient in others ; 
some are low in practically all of the necessary foods ; 
while some soils in arid regions contain excessive quantities 
of soluble salts. This great variation makes clear the 
fact that what is called " soil " is by no means a definite 
thing, but may have almost any composition or structure. 

The soil may be considered as the waste heap of na- 

67 



68 The Princijjles of Agronomy 

ture, since almost everything eventually finds its way 
into the soil where it is mixed and remixed with all sorts 
of substances to make a blanket-covering for the earth. 
Fragments of all kinds of minerals and rocks and the 
remains of all the plants and animals are brought together 
in the soil to make of it a home in which plants may thrive. 

54. Permanence of soils. — The soil cannot be abso- 
lutely destroyed or removed from the earth. It will 
always remain as a heritage to mankind and furnish him 
a means of making a living. Floods may rage, fires may 
sweep over the land, man may be at war, dynasties may 
rise and fall, but the soil will remain an ever-present 
means of producing food. It may be abused and have 
its fertility lessened, but it cannot be entirely destroyed ; 
and, if left to the reviving action of nature, it will in time 
have part of its lost fertility restored. 

55. Economic importance of the soil. — The soil is at 
the very foundation, not only of agriculture, but of all 
human welfare. The industries of man would cease, and 
he would be left without food and clothing if the soil 
should fail to produce its bounties. Mines would close, 
railroads would cease to operate, factories would stop 
their wheels, in fact, every human activity would in time 
be discontinued if the soil should lose its producing power. 

The growth of all cultivated plants is dependent on 
the soil, and the yield of crops is a direct reflection of its 
condition. Since livestock are maintained by crops, the 
livestock industry also depends for its existence on the 
productivity of the soil. 

56. Conservation of the soil. — Of all the national 
resources, the one most in need of conservation is the soil. 
Forests may grow in the lifetime of man, and waterfalls 
will continue after he is gone ; but the soil — the product 
of ages of nature's work — when depleted, can be re- 



What the Soil Is 69 

newed only at great expense. The most important con- 
servation movement, therefore, for any nation to under- 
take is the preservation of the fertihty of its soils. 

57. Need of better soil management. — As a rule, soils 
are tilled by methods handed down from previous genera- 
tions. These may, or may not, be the best methods. 
Most of them were devised at a time when but little was 
known of the real nature of soils or the food of plants, 
and as a result, they do not take into account the factors 
of crop production which are to-day known to exist. 
Many of the present methods of handling soils are out 
of date and are not well founded ; while other methods 
are known which, if adopted, would add greatly to the 
profits of farming. Since the welfare of the natio*ns is 
based on the productivity of the soil, nothing could be 
of greater importance to a country than the discovery of 
better ways of handling its soils and the prompt dis- 
semination of this information to tillers of the land. 



CHAPTER VII 

ORIGIN AND FORMATION OF SOILS 

The material of which the soil is made has been derived 
largely from the rocks and minerals composing the crust 
of the earth ; but in some soils a considerable part is made 
up of vegetable matter from the bodies of dead plants. 
All agricultural soils contain a certain quantity of organic 
matter which is intimately mixed with the mineral matter. 
It is difficult to tell in all cases just the kind of rock from 
which a given soil is derived, since the great amount of 
weathering and mixing often causes it almost to lose its 
original identity. 

58. Minerals and rocks. — A mineral may be defined 
as any solid substance of inorganic origin, occurring in 
nature, and having a practically definite chemical com- 
position and usually a definite crystalline form. A rock 
may be composed of a single mineral ; but it is usually 
made up of an aggregate of minerals associated with 
some impurities. Granite is a rock which contains the 
minerals quartz, feldspar, and mica. Different kinds 
of granites vary considerably in their mineral content. 
Elements unite to form compounds ; compounds are 
united to form minerals ; aggregates of minerals compose 
rocks ; and rocks disintegrate to form soils. 

59. Soil-forming minerals. — It is probable that every 
known mineral occurs somewhere in the soil, since weather- 
ing has been going on for ages, and since every mineral 
that has been exposed to weathering action has been car- 

70 



Origin and Formation of Soils 71 

ried into the soil in great or small quantities. The main 
soil-forming minerals are the following : quartz, the feld- 
spars, hornblende and pyroxene, mica, chlorite, talc and 
serpentine, the zeolites, calcite, dolomite, gypsum, apa- 
tite, and the iron minerals. 

60. Quartz is composed of silicon dioxide, or silica, 
which makes up about 60 per cent of the crust of the earth. 
Both silicon and oxygen are found in a great many other 
minerals, and are present in most rocks. Quartzite is 
composed of fine grains of quartz firmly held together. 
Hornstone and flint, sandstone, jasper, and opal are 
composed mainly of silica. Some soils contain more than 
90 per cent of quartz, which is almost entirely insoluble. 

61. The feldspars are compounds of silicates of potash, 
soda, or lime, one or all, in combination with the silicate 
of alumina. They are prominent ingredients of most 
crystalline rocks. Potash feldspar (orthoclase) with 
quartz and mica forms granite gneiss. Soda and lime 
feldspars form many rocks such as basalt, diabase, diorite, 
and most lavas. The feldspars are decomposed with 
comparative ease by weathering agencies, and are the 
chief sources of clay and potash in the soil. Orthoclase 
contains nearly 17 per cent of potash, while leucite from 
lava contains over 21 per cent. 

62. Hornblende and pyroxene are of nearly the same 
composition, being silicates of lime, magnesia, alumina, 
and iron. They appear to be black, but are in reality of 
a dark green color. They are easily decomposed because 
of two properties: (1) their cleavage, and (2) the fact 
that their iron is readily oxidized. These minerals are 
usually deficient in potash and hence go well with ortho- 
clase feldspar. 

63. Mica is similar in composition to hornblende and 
pyroxene, but its relative insolubility makes its plant- 



72 The Principles of Agronomy 

food elements unavailable. It occurs most abundantly 
with quartz in mica schist which usually forms soil of a 
poor quality. The soils derived from granites and gneisses, 
however, even when rich in mica, are usually excellent 
on account of their feldspar and associated minerals. 

64. Chlorite is a silicate of alumina and iron. It 
forms part of chlorite schist which is similar, but inferior, 
to hornblende schist. Talc and serpentine are hydrous 
silicates of magnesia. They form an important part of the 
soils of some regions, but are very insoluble and are 
usually poor in plant food. 

65. Zeolites are hydro-silicates containing as bases 
chiefly lime and alumina, usually with small quantities 
of potash and soda, and sometimes magnesia and baryta. 
Water is combined in the basic form and not merely as 
water of crystallization. The zeolites proper are not 
original rock ingredients, but are formed in the course of 
rock decomposition by the atmosphere, heated water, 
and other agents. Although zeolites rarely form a 
large proportion of the rock-forming minerals, they are 
of interest because of the continuation within the soil 
of some of the processes that bring about their formation 
in rocks. They are common cementing materials for 
holding together sand grains. 

66. Calcite, or lime, is an important soil-forming min- 
eral, which is but slightly soluble in pure water, although 
much more so in the presence of carbon dioxide. It is 
dissolved readily by acids. Limestone comes partly 
from the shells and framework of marine and fresh water 
animals and partly by concretions of lime directly from 
water; hence much of it has been dissolved and precip- 
itated many times. The old saying that " A limestone 
country is a rich country," has, on the whole, but few 
exceptions. 



Origin and Forviation of Soils 73 

67. Dolomite, a mixture of calcium carbonate and 
magnesium carbonate, is more easily affected by weather- 
ing agents than pure Hmestone. An excess of magnesia 
tends to impoverish soils. 

68. Gypsum, or the sulfate of lime, although widely 
distributed, is not so abundant as limestone. Few nat- 
urally gypseous soils are very productive, probably 
because of the heavy clays w^hich usually accompany 
this compound. Gypsum favors the action of certain 
desirable bacteria, and it is sometimes used to correct 
black alkali. 

69. Apatite, the phosphate of lime, is found in many 
soils. Unless accompanied by organic matter, it is rather 
unavailable. 

The most important iron minerals in the soil are sider- 
ite, limonite, hematite, and magnetite. Since iron is 
always present in sufficient quantities for plant growth, 
the iron compounds need receive but little attention. 

70. Soil-forming rocks. — The individual minerals, 
not usually occurring separately, are combined and mixed 
with the various igneous and sedimentary rocks. Rocks 
rich in feldspar are said to be feldspathic ; in clay, argil- 
laceous ; in silica, siliceous ; in lime, calcareous ; and in 
sand, arranaceous, according to the minerals composing 
them. These various rocks in decomposing form soils 
which differ greatly. 

Soils from granite with potash feldspar are rich in 
potash and usually contain an ample supply of phosphoric 
acid from small apatite crystals. Gneiss soils are more 
siliceous and less strong than those from true granites. 
Eruptive rocks as a class usually form very productive 
soils, but decompose slowly. Hard limestone dissolves 
slowly, but the softer varieties go into solution readily. 
Limestone soils from which much of the lime has been 



74 The Principles of Agronoimj 

leached form some of the very richest soils. The Ken- 
tucky blue-grass region is an example of soil formed in 
this way. Sandstone soils are often poor, but this de- 
pends on the material cementing the grains together. 
Claystone soils are usually rich in plant-food material, 
but are too heavy for the best growth of crops. Hard- 
pans are formed where an excess of alkali accompanies 
the clay. 

71. Methods of soil formation. — Soils are formed 
from the minerals and rocks, already discussed, by the 
various chemical and physical agencies of rock decay 
known as weathering. The most important of these 
agencies are: (1) heat and cold, (2) water, (3) ice, (4) 
the atmosphere, and (5) plants and animals. Their ac- 
tion is both mechanical and chemical, the mechanical 
causing a breaking up of the rock into Jfiner fragments, 
and the chemical causing a change in the actual composi- 
tion of the materials. 

72. Action of heat and cold. — All of the weathering 
agents may be ultimately traced back to the heat of the 
sun, the source of energy for the earth. Wind, rain, 
and organisms are all directly dependent on this source 
of heat. In addition to this general work, heat and cold 
are strong factors working directly in breaking down rock 
masses. This is very apparent in the granites, gneisses, 
and mica-schists, each composed of a number of minerals 
which expand unevenly when heated, causing a break 
in the rock. This allows water to enter. When cold 
weather comes the water freezes, and, in freezing, expands 
about 9 per cent of its volume. This widens the crevice 
and shatters the rock. Thus, nature uses heat and cold 
as charges of powder which are constantly being dis- 
charged to assist in the constant effort to crumble the 
rock-masses into soil. 



Origin and Formation of Soils 75 

73. Action of water. — Water through its physical 
and chemical action is perhaps the most important of 




Fig.. 16. — Streams wear gorges, grinding rocks into fine particles. 

the weathering agents. In mountain torrents, bowlders 
are rolled along, knocking and rasping in their ceaseless 



76 The Principles of Agronomy 

effort to loosen the banks and gouge out the bottom of 
the stream. In the meantime, the rolling bowlder is 
ground into countless particles, which in the course of 
time are scattered over as many acres of land. The 
gorges of the Columbia and Colorado rivers, w'hich, in 
places, are thousands of feet deep, are good examples 
of abrasive action. All this earthy material is carried 
downstream. The Mississippi River annually carries 
into the Gulf of Mexico enough earth to cover a 640 acre 
field 286 feet deep. In addition to this, it deposits im- 
mense quantities of silt along the lowlands above its 
mouth. Effects of water action are shown in Figs. 16 
and 17. 

The ability of water to carry suspended material varies 
as the sixth power of its velocity ; hence, as the grade of 
a stream changes and the quantity of water varies, there 
is a constant unloading and reloading of transported 
materials. Rains, by their constant pounding, also 
exert considerable action on rocks, especially in loosening 
and shifting small fragments. 

Water is called nature's universal solvent. Its power 
to dissolve is greatly increased by the presence of carbon 
dioxide which it takes from decaying organic matter while 
percolating through the soil. Waves and tides along 
the sea-shore move sand and other materials in and out, 
up and down, and by their continuous pounding often 
wash out great caverns. 

74. Ice. — In mountainous countries, where there is 
considerable snowfall, snowslides are of common occur- 
rence. One of these slides often contains thousands of 
tons of sliding and rolling snow^ and moves everything 
in its way. Trees, rocks, and all kinds of debris are 
jammed into the caiions below to be taken out by swollen 
streams. 



Origin and Formation of Soils 



77 



Ice in the form of glaciers is in certain regions a power- 
ful agent in the making of soils. Glaciers are both dis- 
integrators and transporters ; lateral, medial, and termi- 
nal moraines are formed from the transported material. 




Fig. 17. — Soils are often deposited and moved many times before being 
used for crop production. 



and the rock over which the glacier moves is ground into 
a very fine powder, which is often carried away by the 
streams resulting from the melting ice. The river from 
the Aar glacier carries away 280 tons of solid matter in 
suspension daily. The Justedal, which covers an area 



78 The Principles of Agronomy 

of 820 square miles, discharges on a summer's day 1968 
tons of sediment besides the material in solution. The 
Vatnajokull glacier in Iceland discharges annually about 
14,763,000 tons of earth. 

These glaciers of to-day are mere babies when compared 
with those that existed during the great ice age, when 
the ice sheet covered 2,500,000 square miles. The effects 
of this ice sheet are apparent all over the northern part 
of America, Europe, and Asia. The soils of these regions 
are of glacial origin, and are very fertile in potential plant- 
food, but often lack in oxidation and tilth. Glacial soils 
are very different in structure from those formed by the 
slower process of disintegration. They are usually uni- 
form to considerable depth. In the northern part of the 
United States and over a large part of Canada, there is 
a layer of this well-mixed soil resulting from the North 
American ice sheet. 

75. The atmosphere. — The atmosphere exerts both 
physical and chemical action. Its physical work is done 
mainly through winds, which are most effective in regions 
of little vegetation. In parts of China, the wind-formed 
soils, or loess, are from 1500 to 2000 feet deep. The 
chemical action of the atmosphere is due almost entirely 
to oxygen and carbon dioxide. The action of the latter 
in increasing the solvent power of water has already been 
explained. Oxygen, working as an oxidizing agent, affects 
most of the minerals composing the soil. The minerals 
containing iron are oxidized when brought in contact with 
air, with the result that their rocks are softened. Feldspar, 
in the presence of air, oxidizes to kaolin ; and certain rocks 
containing large quantities of feldspar often crumble to a 
depth of forty or fifty feet by the action of the atmosphere. 

76. Plants and animals join with other agencies in 
breaking up rocks and mellowing soils. Some of the 



Origin and Formation of Soils 79 

lower forms of plants are able to begin their growth on 
almost smooth rock surfaces, and by the dissolving ac- 
tion of their juices, soon make sufficient impression to 
enable other plants to start and to permit the entrance of 
water. This, by its dissolving and freezing action, has- 
tens decay. Roots of higher plants readily penetrate 
any small crevice and by their gigantic strength are able 
to break even large bowlders. The smaller roots of plants 
penetrate every particle of earthy material and by their 
physical and chemical activities promote the formation 
of a good agricultural soil. 

Burrowing animals and earthworms are constantly at 
work mixing the various soils, incorporating organic mat- 
ter, and assisting in the free movement of air. Plants 
and animals are constantly dying, and their bodies con- 
tribute to the organic matter of the soil, which ceases to 
be just a mass of dead matter. The decay of these organic 
bodies assists, not only in mellowing the soil and placing 
it in a better physical condition, but also in the making 
available various plant-foods. 

77. Classification of soils. — Soils may be classified 
according to their or^in as either s eden tary or transported. 
Sedentary soils are of two kinds : those which over-lie 
the rock from which they were formed, and those formed 
in place largely by the accumulation of organic matter, 
as in swamps. Transported soils vary with the agent 
used in carrying the materials of which they are composed. 
Those transported by running water are called alluvial ; 
by ice, glacial ; by wind, feolian ; and by the ocean, 
marine. Each of these kinds of soils has its own peculiar 
properties, although the composition is dependent largely 
on the kind of rock from which it was formed. 

In addition to classification according to origin, soils 
are sometimes classified by their chemical composition, 



80 The Principles of Agronomy 

the native vegetation growing on tliem, the crops to 
which they are suited, the size of particles composing 
them, and a number of other properties. Any adequate 
method of classifying soils, however, should take account 
of all the factors which affect their value. 



SUPPLEMENTARY READING 

Soils, Lyon, Fippin, and Buckman, pp. 1-82. 

Soils, E. W. Hilgard, pp. 1-62. 

Any textbook of physiography or geology. 

Agricultural Analysis, H. W. Wiley, pp. 1-60. 

The Soil, F. H. King, pp. 1-69. 

The Soil, A. D. Hall, pp. 6-31. 

Cyclopedia of American Agriculture, Vol. I, pp. 324-342. 

Physics of Agriculture, F. H. King, pp. 49-68. 



CHAPTER VIII 
PHYSICAL PROPERTIES OF THE SOIL 

The soil is composed of fine rock particles of different 
sizes thoroughly mixed with varying quantities of organic 
matter in different stages of decomposition. For practi- 
cal purposes, it is divided into the surface and sub-soil, 
the sub-soil being the part below the plowed zone. Soils 
vary greatly in their general make up, some being but a 
few inches deep and overlying solid rock, while others are 
hundreds of feet deep and fairly uniform throughout. 
Every gradation between these two is found, including 
clay surface soil with gravelly sub-soil or gravelly surface 
with clay below. In arid regions the difference between 
the surface and sub-soil is not great, the sub-soil being in 
many cases just as fertile and mellow as the upper layer. 
In humid regions, however, the sub-soil is often compact 
and, on account of its lack of aeration, seems " dead " 
when brought to the surface. Such soil sometimes re- 
quires a number of years to become friable. 

78. Soil texture. — Soils vary greatly in the size of 
particles composing them. Some are made up almost 
entirely of coarse particles ; others are composed entirely 
of fine. ]\Iost soils, however, contain some fine and some 
coarse grains, the relative number of each determining the 
texture, which cannot be modified by the farmer. The 
texture of a soil has a great influence on the method of 
tillage as well as on a number of its properties, such as 
G 81 



82 



The Principles of Agronomy 



the water-holding capacity, the circulation of air, and 
the availability of plant-food. These all help in determin- 
ing the kind of crop that should be grown. For example, 
peaches and cherries do best on soils having a coarse 
texture; the small grains prefer a " heavier " soil. Soils 
having an intermediate texture, such as the loams, are 
fairly well adapted to the raising of any ordinary crop. 
Hence, in selecting land, the farmer who knows what 
crops he wishes to grow should give considerable atten- 
tion to soil texture. 

79. Groups according to texture. — The soil may, by 
mechanical analysis, have its particles separated in such 
a way that all grains of approximately the same size are 
gathered together. Where this is done, arbitrary groups 
are arranged for convenience in expressing the sizes. A 
number of different methods of grouping have been em- 
ployed, but probably the one finding widest use in this 
country is that of the Bureau of Soils of the United States 
Department of Agriculture. In this grouping the various 
sizes are given the following names : 



Name 


Diameter in 

Millimeters 


Number of 

Particles in 

Gram of Soil 


1. Fine gravel 

2. Coarse sand 

3. Medium sand 

4. Fine sand 

5. Very fine sand 

6. Silt 

7. Clay 


2.000-1.000 
1.000-0.500 
0.500-0.250 
0.250-0.100 
0.100-0.050 
0.050-0.005 
less than 0.005 


.252 

1,723 

13,500 

132,600 

1,687,000 

65,100,000 

45,500,000,000 



It is impossible to get a soil composed entirely of 
particles of any one size; hence, the name given to a 



Physical Properties of the Soil 



83 



soil type must depend on the relative mixture of these 
various sizes. The terms most commonly used for these 
mixtures are: (1) coarse sand, (2) mediiun sand, (3) fine 
sand, (4) sandy loam, (5) loam, (6) silt loam, (7) clay 
loam, and (8) clay. Farmers, speaking in a general way, 
usually call their soil sand, loam, or clay. 

80. Relation of texture to water-holding capacity. — 
Of the properties of soils affected by texture, probably 
none is of greater practical importance than the water- 
holding capacity. Moisture is held in thin films around 
the soil particles and the quanity that can be retained 
depends largely on the surface, which in turn is dependent 
on the size of particles. King gives the surface of soils 
of different sizes as follows : 



Diameter of Grains 


Sq. Cm. Surface to 


Sq. Ft. Surface 


IN Millimeters . 


A Gram of Soil 


TO A Lb. of Soil 


1.0 


22.64 


11.05 


.1 


226.41 


110.54 


.01 


2,264.15 


1,105.35 


.001 


22,641.51 


11,053.81 


.0001 


226,515.14 


110,538.16 



With such a great variation in surface, it is easy to see 
why a clay soil may hold 45 per cent of water when a 
coarse sand will scarcely hold 15 per cent. The under- 
standing of this fact is important in such branches of 
agriculture as dry-farming, where success depends on the 
storage in the soil of large quantities of water. 

81. Soil structure. — Structure refers to the arrange- 
ments of soil particles. Just as sticks may be piled in a 
box in various ways, so the soil grains may be grouped in 
numerous different arrangements. Sticks may be piled 



84 The Principles of Agronomy 

evenly all one way and fitted together in such a manner 
that there is little air space between ; they may be ar- 
ranged with one layer crosswise, the next lengthwise, 
or in other designs, each arrangement having a different 
volume of air space between the sticks. The same soil 
particles may, in a similar manner, have many different 
groupings. The numerous sizes of particles present in 
every soil make an even more complex arrangement 
possible. The grains may be wedged tightly together so 
that air is almost excluded, or they may be flocculated 
into loose-fitting groups with considerable air space 
between. 

The tilth of a soil, known by farmers to be of such great 
practical importance, is determined by its structure, or 
the grouping of its particles. Soil grains packed tightly 
together form a soil of poor tilth. When plowed, such a 
soil breaks up into clods instead of falling apart in granules 
or floccules. A loose structure gives lines of weakness 
extending in every direction through the soil. Where 
such a condition exists, it cannot be made to hold together ; 
but where the opposite condition exists, the soil crumbles 
only when considerable force is applied. A hardpan 
structure in arid soil is shown in Fig. 18. 

82. How to modify structure. — The structure of a 
coarse-grained soil cannot be greatly affected, since it is 
always fairly good ; but with a clay, constant care is 
necessary to prevent its becoming puddled. Many a 
farmer has learned through sad experience that he can, 
by cultivating a clay soil when too wet, so injure the tilth 
that several years are required to get the soil back into 
good condition. 

The structure of a soil is affected by almost everything 
that causes a movement of soil particles. Among the 
most common factors are the following: (1) tillage, (2) 



Physical Properties of the Soil 



85 






^Sk'r*' 






^%? 











Fig. 18. — Hardpan in arid soil three feet below surface. 



86 The Principles of Agronomy 

the growth of roots, (3) freezing and thawing, (4) alter- 
nate wetting and drying, (5) organic matter, (G) sohible 
salts, (7) animal life, and (8) storms. The tilth is the 
result of the combined action of a number of these factors, 
all of which improve it except certain kinds of storms like 
hail, and certain soluble salts like sodium carbonate, 

83. Specific gravity of soils. — The weight of a soil 
may be expressed as the real or the apparent specific 
gravity. The real specific gravity, referring to the weight 
of the individual particles in comparison with water, is 
not affected by the pore-space. The apparent specific 
gravity, on the other hand, refers to the relative weight 
of a given volume of soil and the weight of the same 
volume of water. This is greatly afi'ected by pore- 
spaces. 

Clay is often spoken of as a " heavy " soil ; sand is said 
to be " light." This does not refer to weight, but means 
that clay is difficult, and sand easy, to till. An average 
sand weighs about 110 pounds to the cubic foot, but clay 
weighs only about 80 pounds. 

84. Air in the soil. — Since air is necessary to the 
growth of all plants, it is impossible to have a fertile soil 
without spaces through which air can circulate. Seeds 
in germinating, and plant roots in growing, require oxygen 
which is absorbed while carbon dioxide is given off. 
The decay of organic matter requires oxygen and forms 
carbon dioxide, which accumulates in the soil-air with 
the depletion of oxygen. If the condition of the soil 
does not favor the free movement of air, the oxygen supply 
soon becomes reduced to the point where plant growth is 
retarded. The aeration of the soil is dependent on its 
texture, structure, drainage, and a number of other 
factors. In a coarse sand air moves readily, but in a clay, 
especially if compact, the movement is slow. Puddling 



Physical Properties of the Soil 87 

a soil greatly retluces its aeration, while flocculating its 
particles into groups promotes the ready movement of 
air. The size of particles cannot be changed, but their 
arrangement is affected by plowing and harrowing, which 
thereby indirectly influence aeration. 

A water-logged soil usually has its producing power 
reduced by lack of oxygen; and the free circulation of 
air, resulting from placing tile drains under such a soil, 
is in part responsible for the increased yields following 
drainage. The beneficial nitrifying and nitrogen-fixing 
bacteria of the soil require an abundant supply of oxygen 
for their best growth, and their action is practically 
discontinued when the air supply is reduced below a 
certain point. In some soils the aeration may be so 
great as to result in the loss of excessive quantities of 
water. This condition, however, is rarely met, and may 
be remedied in most cases by packing. 

85. Heat of the soil. — The temperature of the soil 
is important because of its influence on the germination 
of seeds and on the growth of plants ; also because of its 
effect on chemical changes and bacterial action in the 
soil. When the soil is cold, its life is dormant and all 
chemical action is reduced. The earlier a soil is warmed 
in the spring and the later it is kept warm in the fall, 
the longer is its growing-season. This may have con- 
siderable practical importance in regions where early crops 
bring the best prices and where the season is so short 
that crops do not fully mature. 

Soil heat comes largely from the sun, the rays of which 
are most effective when striking perpendicularly. A 
south slope, therefore, is considerably warmer than one 
facing the north, and a sandy soil is much warmer than 
clay. The high specific heat of water makes it slow to 
warm, and as a consequence, a wet soil is usually late in 



88 The Principles of Agronomy 

starting the growth of plants in the spring. The exces- 
sive evaporation from a wet soil also reduces its tempera- 
ture. Such factors as color, specific heat, tillage, and a 
number of others play a very important role in regulating 
the temperature of a soil. 

86. The organic matter of the soil is without doubt one 
of its most iin])ortant parts since it influences so greatly 
the physical, chemical, and biological changes that take 
place. The tilth of a soil, its water-holding capacity, its 
temperature, and a number of other physical properties 
are improved by the presence of organic matter, which, 
on decaying, increases the availability of mineral matter 
in the soil and hastens desirable chemical changes. 
Bacteria, which are so important to the soil, could not do 
their work without organic matter, since they secure their 
energy by its decomposition. The fertility of a soil, 
therefore, depends as much on the presence of organic 
matter as on any other factor ; and the maintenance of 
fertility must include the keeping up of this important 
constituent. 

87. Maintaining the organic matter. — The organic 
matter of soils is derived largely from the decay of roots, 
leaves, and stems, although a part of it comes from the 
remains of animals. For ages, accumulation has been 
going on until some soils have a large percentage of organic 
material. In arid soils, however, where the growth 
of vegetation has been light, the organic content is 
low ; hence, one of the chief problems in the manage- 
ment of arid soils is to increase the proportion of organic 
matter. 

Organic matter in the soil is maintained by the addition 
of farm manure and other organic refuse, and by the 
raising of crops to be plowed under. The wise farmer 
will, if possible, apply large quantities of manure in order 



Physical Properties of the Soil 89 

to maintain organic matter as well as to add plant-food. 
The continuous raising of grain crops on the same land 
year after year and the burning of straw and stubble is a 
procedure most ruinous to land. The regular use of 
green-manure crops, preferably the legumes, and the 
returning of all plant residues to the land will serve to 
maintain the proper proportion of organic matter in the 
soil. 

SUPPLEMENTARY READING 

Soils, Lyon, Fippin, and Buckman, pp. 83-197. 

Physical Properties of the Soil, R. Warington. 

Soils, E. W. Hilgard, pp. 83-187. 

Fertilizers and Crops, L. L. Van Slyke, pp. 117-144. 

'i'he Soil, A. D. Hall, pp. 60-88. 

Physics of Agriculture, F. H. King, pp. 49-68. 

Cyclopedia of American Agriculture, Vol. I, pp. 349-357. 



CHAPTER IX 
THE WATER OF THE SOIL 

All plants and animals require water for life and growth. 
Plants may live for considerable time without receiving 
any outside supply of mineral food, but if water is with- 
held, they very soon wilt and cease to function. The 
yield of crops fluring any particular year is usually a 
^reflection of the moisture conditions during the growing- 
season. Even in humid regions, the lack of available 
moisture often reduces crop-yields. Over more than 
half of the earth's tillable surface, the shortage of moisture 
is the chief limiting factor concerned in crop growth ; 
while in parts of the humid regions, the excess of water in 
the soil prevents the cultivation of vast areas of otherwise 
fertile soil. On the whole, therefore, no factor connected 
with agriculture needs to be more carefully studied and 
more thoroughly imderstood than the water of the soil. 

88. Origin of soil water. — The water of the soil has 
Jit some time been precii)itated from the atmosphere. 
That contained in the soil of any given field may have 
come in by percolation, or by flooding the surface ; but 
it has at some time been vapor. The quantity of mois- 
ture in the soil of any large area, therefore, will be de- 
pendent on the precipitation of that region. The rain- 
fall cannot be influenced by man, but he can do much to 
save water after it falls. In dry regions he may increase 
the amount of soil water by irrigation, or he may reduce 

90 



The Water of the Soil 91 

it by drainage wlien there is too nnich for the best growth 
of the erops. He may also inerease tlie efficiency of the 
moisture in the soil by certain tillage operations. 

89. Variations in soil moisture. — The quantity of 
moisture in the soil is not so stable as the phosphorus, 
lime, or silica ; but it varies from season to season and 
from day to day. It seldom remains the same even for 
a short period. More is being added from time to time, 
and losses occur through a number of channels. Even 
if for a short period no water is added or lost, there is a 
constant movement from place to place with a tendency 
to establish an equilibrium which is seldom, or never, 
reached. Many forces are at work making it difficult 
to determine all the laws by which soil moisture is in- 
fluenced. 

90. The condition of the soil moisture depends largely 
on the quantity present and the nature of the soil. If 
the soil is saturated, the action is not the same as if only a 
small quantity of water is present. The soil is able to hold 
only about a certain amount of moisture and when more 
is added it percolates rapidly. As the quantity decreases, 
the tenacity with which it is held increases. A sandy 
soil reaches the point of saturation with much less water 
than does a clay soil. The condition of the moisture, 
therefore, will not always be the same with a given per- 
centage, but will vary according to the nature of the soil. 

The water of the soil is usually divided into three 
classes, determined by the percentage present. These 
are: (1) free, or gravitational, (2) capillary, or film, and 
(3) hygroscopic water. 

91. Free water. — When the soil becomes saturated 
with water, a part of it drains away, due to the action of 
gravity. This drainage water is known as free, or grav- 
itational, water. The attraction of the soil for it is not 



92 The Principles of Agronomy 

so great as that of gravity. This water is found between 
the grains of soil, taking the place of air. Gravitational 
water, held in surface soil for any great length of time, 
excludes tiie air needed by roots. Normally, after a 
heavy rain, the top soil has its air spaces filled with 
water, but this rapidly sinks to moisten the drier soil 
below, in which case it ceases to be free water. Drainage 
is practiced to remove the free water that cannot drain 
away unaided. 

92. Capillary water. — After all the free water has 
drained out of the soil, there is still remaining a great 
deal of moisture that is held in a thin film around each 
soil particle. Most of the water in ordinary cultivated 
soils under field conditions is of this nature, and it is 
this form that supplies water to plants. The quantity 
of capillary water that can be held by a soil depends on 
the surface area of its particles. Since many fine particles 
have more surface than a large one occupying the same 
volume, a fine-grained soil, such as clay, will hold much 
more* film water than a coarse-grained soil like sand. 

Capillary water moves by going from the wetter to the 
drier particles in the soil. The films on different soil 
grains tend to become of the same thickness, thus exert- 
ing a pull on the thicker films. 

93. Hygroscopic water. — A part of the moisture is 
retained by the soil even when it seems to be dry. Road- 
dust, on being heated, will give off water vapor which 
may be condensed on a cold body. This last moisture 
which a soil retains is called hygroscopic water. If a 
soil is dried completely with heat and then allowed to 
stand in the open, it will absorb moisture from the air. 
This water is held in a thin film around the particle in a 
way similar to that in which capillary water is held, only 
much more firmly. It does not move from particle to 



The Water of the Soil 93 

particle as does the capillary water. Hygroscopic water 
is of no direct use to plants, since the soil has a greater 
attraction for it than have the plants. 

94. Other critical points. — It has been shown in late 
years that there are a number of critical points in the 
percentage of soil moisture besides those already men- 
tioned. For example, there is a point at which plants 
wilt. This occurs when there is a small quantity of 
capillary water in addition to the hygroscopic water. 
There is another point in the capillary water below which 
the movements are very slow. Above this point the 
capillary movement is much more rapid. 

95. Quantity of water in field soils. — The quantity 
of moisture found in field soils depends on a number of 
conditions. Of these, the amount and frequency of 
rainfall is perhaps most important. In arid regions, 
the soil is seldom near the point of saturation, while 
in regions of great rainfall, it is kept constantly wet. 
Every gradation between these extremes is found. The 
amount of moisture that a soil will hold depends almost 
entirely on the size of particles and the amount of organic 
matter which it contains. The finer the soil the greater 
its water capacity, A clay that seems fairly dry really 
contains more water than a moist sand. In one experi- 
ment the maximum water-holding capacity of different 
classes of soils was as follows : 

Sand 8 per cent 

Silt loam 25 per cent 

Clay 40 per cent 

The clay was able to retain five times as much as the 
sand. Organic matter, or humus, greatly increases the 
power of soils to retain water. This is one reason why 
much humus is desirable. 



94 The Principles of Agronomy 

96. Methods of expressing the quantity of water. — 

Soil moisture is usually expressed in percentage of the 
soil by weight. This may be based either on the total 
weight of the soil and water, or on the dry soil alone. For 
example, if on heating 100 pounds of soil there was a 
loss of ten pounds, there would be 10 per cent of water 
on the wet basis, there being ninety pounds of soil and 
ten pounds of water. On the other hand, since ten pounds 
is 11.1 per cent of ninety pounds, there would be 11.1 per 
cent of water in the soil on the dry basis. The quantity 
of water may also be expressed in percentage of the soil 
by volume. The depth of water over the surface of a 
given area of land is a common method of expressing 
quantity in an irrigated district. 

97. Loss of soil moisture. — The water that falls on 
the soil can be lost in three ways: (1) run-off from the 
surface, (2) percolation through the soil, and (3) evapora- 
tion from the surface. 

In arid regions, it is desirable to reduce run-off to 
a minimum, but it may be necessary to increase it in 
sections of excessive rainfall. Too much run-off under 
any condition is undesirable, as it is likely to cause de- 
structive erosion. This loss is diminished by keeping 
the soil open and receptive in order that it may absorb 
the rain as fast as it falls. Percolation can be reduced 
only by increasing the water-holding capacity of the soil. 
This is done by keeping the soil loose and increasing its 
organic matter. 

The loss by evaporation is, in part, under the control 
of man. When moisture is once in the soil, it should be 
held there until needed by plants. This is accomplished 
by some protecting cover such as a mulch. 

98. Need for preventing evaporation. — The plant 
gets its moisture from that stored in the soil ; hence, if 



The Water of the Soil 



95 



the supply runs short, the plant suffers. Even in humid 
climates, rain is so uncertain that it is not safe to let the 
soil become dry by evaporation. In arid regions, it is 
absolutely necessary to store all the water that falls, or 
there will not be sufficient to produce crops (see P'ig. 19). 
Almost the whole practice of dry-farming is founded 
on the prevention of this loss. Evaporation from the 
soil is affected by the same factors as evaporation from 
a water surface. Heat, wind, sunshine, air humidity, and 




Fig. 19. — Reservoir for the storage of irrigation water. 



altitude all play their part. With soil, an important 
consideration is the wetness of the surface. Drying the 
surface quickly is one method of preventing loss. 

99. The water-table is the level in the soil at which 
free water is encountered. In digging a well, the place 
where water is found is known as the water-table. The 
depth of the water-table below the surface varies — from 
a few inches in swamps to many hundreds of feet in some 
arid sections. It is undesirable to have water too near 
the surface, as roots cannot penetrate below water level. 
A changing water-table near the surface is especially bad, 



96 The Princijjles of Agronomy 

since roots no sooner get established than water rises and 
kills them, thereby weakening the entire plant. The 
chief reason for draining soils is to lower the permanent 
level of the water-table or to prevent its rising to injurious 
heights during wet seasons. 

100. The movements of soil-moisture are due to a 
number of distinct forces. Gravity is constantly pulling 
the moisture down wherever there is free water. After 
this has been removed, however, gravity does not have 
much effect. The capillary water is moved by force of 
surface tension which works to make the films on soil 
particles of equal thickness. When water is removed 
from part of the soil, the film thickness is reduced and 
there is a gradual movement in that direction. If there 
is evaporation at the surface or if roots remove moisture 
from below, this force of capillarity, or surface tension, 
draws water from other parts. When there is much 
film water present, the movement is comparatively rapid ; 
but as the soil approaches dryness, it greatly diminishes, 
and finally ceases. A little water is moved from place 
to place in the soil by what is known as thermal action. 
There is an evaporation of water from one place in the 
soil and a condensing of it in another. Movements by 
this method are slow and of little importance. 

101. Uses of soil water. — The principal use of the 
soil water is to supply the needs of plants — crops cannot 
be produced without it. Soil water also acts as a carrier 
of plant food. The plant can take up only food that is 
in solution ; consequently, without a proper amount of 
water no other food can be obtained. Water also in- 
creases the chemical action that goes on in the soil, making 
soluble the substances used by crops. 

102. Quantity of water used by plants. — A plant 
may use two or three times as much water each day as 



The Water of the Soil 97 

its own weight. Every living, active plant-cell contains 
a large quantity of water, and the process of photosyn- 
thesis calls constantly for it. The greatest use plants 
have for water, however, is for transpiration. For each 
pound of dry substance produced, there must be a number 
of hundred pounds of water transpired. This intimate 
relationship existing between the soil moisture and the 
life of the plant makes water the most important, as it 
is also the most variable, factor in crop production. 

SUPPLEMENTARY READING 

Soils, Lyon, Pippin, and Buckman, pp. 198-288. 

Soils, E. W. Hilgard, pp. 188-266. 

The Soil, A. D. Hall, pp. 67-119. 

The Soil, F. H. King, pp. 135-183. 

Cyclopedia of American Agriculture, Vol. I, pp. 408-412, 

Dry-farming, J. A. Widtsoe, pp. 94-129. 

Physics of Agriculture, F. H. King, pp. 158-203. 

Principles of Irrigation Practice, J. A. Widtsoe, pp. 9-63. 

Physical Properties of the Soil, R. Warington, pp. 51-138. 



CHAPTER X 

THE CONTROL OF SOIL WATER 

In agriculture it is often desirable to change the amount 
of water present in the soil. Where it is necessary to 
remove the excess of water, this is done by drainage, 
while if the land is dry, its water content may be increased 
by irrigation. Under arid conditions, where irrigation 
water is not available, it becomes necessary to adopt 
methods of conserving a scant precipitation in the soil 
for the use of crops. This is accomplished by the methods 
of dry-farming. 

IRRIGATION 

103. Increasing the soil moisture. — In all arid, and 
even in some humid, regions there are times when the soil 
moisture is not sufficient for the best growth of crops. 
Where this condition exists during any great part of the 
time, it is often advisable to add water to the soil by 
irrigation. Methods of conducting this water are shown 
in figures 20 to 24. 

This method has many advantages as well as some dis- 
advantages. A person would think himself very fortu- 
nate if he could cause it to begin and cease raining at will, 
yet with irrigation water at his disposal, a farmer can do 
even more. He can not only have water when needed, 
but he can apply it to one crop and at the same time 

98 



The Control of Soil Water 



99 




P'iG. 20. — Water being taken to the land. 




Fig. 21. — Cemcut lining pl'L•^•(-'nt,^ ticepagt'. 



100 



The Pmiciples of Agronomy 



withhold it from another such as newly-cut hay that 
might be injured at the time by water. The rain, even 
supposing it to be under the farmer's control, would fall 
on the entire farm if it came at all. 

Among the disadvantages of irrigation are the cost of 
installing the system and the expense of applying water. 




Fig. 22. — Water diverted from reservoir through tunnel in rock. 



In arid regions, however, these expenses are justified by 
increased profits when the water is used with wisdom. 

104. Sources of water supply. — The most common 
and least expensive source of water for irrigation is found 
in running streams. A suitable dam is placed across the 
bed of a stream to turn water into the canal, which carries 
it to the land that is to be served. The head of such 



The Control of Soil Water 



101 



canals is sometimes many miles from the farm, and at 
other times the land to be irrigated is along the banks of 
the stream. 

Where irrigation water is secured directly from a 
river, only part of the water can be used, since the season 




Fig. 23. — A good type of weir for measuring irrigation water. 



of irrigation is but three or four months out of the year, 
while the stream usually flows continuously, often having 
its greatest flow w^hile the water is not being used. In 
order to make more water available, storage reservoirs 
are built. These receive the water at times when it is 



102 



The Principles of Agronomy 



not being used and hold it for the cropping season. As 
more land is taken up and water becomes less plentiful, 
storage usually increases and methods for accomplishing 
it become complex and thorough. The pumping of 
underground water from wells for irrigation is rapidly 
increasing in many sections. 

105. Measurement of water. — Irrigation water, as 
well as land and crops, should be measured. In the past 
it has been the custom to guess instead of taking accurate 




Artesian water is often used for irrigation. 



measurements. This has led to endless disputes and 
trouble. In the future it will be necessary for those con- 
cerned with the use of water to be familiar with methods 
of making measurements and expressing quantities. 

The two principal devices for measuring flowing water 
are the weir and the current meter. With the former a 
measuring gate of a known size is placed in the stream and 
the height of water flowing over it determined. From 
standard tables the discharge is found. When the cur- 
rent meter is used, the velocity of the stream flow is ob- 



The Control of Soil Water 



103 



tained, together with its cross-section, and from these 
the amount of water is calculated. 

Of the many ways of expressing quantities of water, 
the ones in most common use are the second-foot and the 
acre-foot. A second-foot represents one cubic foot of 
water flowing each second ; an acre-foot is the amount of 
water required to cover an acre of land one foot deep, 
that is, 43,560 cubic feet. A second-foot flowing for 
twelve hours will flow almost exactly an acre-foot. 

106. Methods of applying water. — The four principal 
methods of applying water to land are: (1) furrow, (2) 




Fig. 25. — -Irrigation watm- hcin 



flooding, (3) overhead, and (4) sub-irrigation. The 
first two are by far the most important, but the last two 
are extremely valuable sometimes. The furrow method 
of distribution is shown in Fig. 25. 

In the first method, water is run in furrows and allowed 
to soak the ground between the rows. It can well be 
used on crops that are intertilled and has the advantage 
of not wetting the entire surface. This reduces evapora- 



104 The Principles of Agronomy 

tion greatly as compared with flooding. A small stream 
of water can irrigate a greater area of land by this than by 
other methods, but more labor is required. 

The flooding method is used most on pastures, meadows, 
and the small grains. This method leaves a soil that 
bakes in a crusted condition, and can be used only on 
land with an even slope. Overhead-irrigation is used 
for lawns and gardens, but is never practiced on a large 
scale. Its disadvantages are the high cost of installing 
and the large evaporation. It has the advantage of 
supplying water evenly over the surface in a condition 
similar to rain that leaves the air as well as the soil damp. 

Sub-irrigation is practiced by filling deep ditches on 
the sides of the field with water and allowing it to soak 
through the soil and saturate the sub-soil without wetting 
the surface. It may also be distributed through under- 
ground pipes. The latter method is probably the most 
economical way of using water, since it reduces evapora- 
tion to a minimum. 

107. The amount of water to use will depend, to 
a considerable extent, on the amount available.^ As a 
general rule, however, if there is an abundant supply, most 
farmers will apply more than is good for either the crop 
or the soil. They try to make up for lack of tillage and 
manure by the application of water. 

Crops vary in their water requirements, and even the 
same crop does not require the same quantity of water 
in all climates and on all soils. These factors must be 
taken into account in determining how much to use. 

It is probable that two feet of water applied during the 
year is enough for most crops if the rainfall is as much as 
twelve inches. The yield may be slightly increased if 
more than this amount is used, but the cost of applying 
the extra water is probably more than the increased 



The Control of Soil U'^ater 



105 



yields justify. The practice of putting from six to eight 
feet of water on land in a season cannot be too strongly 
condemned. It wastes water, injures the quality of 
the crop, and reduces the value of the land. 

108. When to irrigate. — It is probable that there is a 
definite amount of moisture that is best for each crop. 
The ideal condition is to maintain this degree of wetness, 
but it is impossible to do this exactly. Crops have cer- 




FiG. 26. — Cement dividing gates save trouble. 



tain periods in their lives when they are especially affected 
by drouth. With grain crops, this sensitive period comes 
when the heads are forming and filling. Sufficient water 
should be supplied at these critical periods. 

Good germination and a good start are very important. 
If sufficient moisture is supplied at first to make this 
possible, plants can often go without much additional 
water till they are preparing to fruit. Forage crops, in 
order to produce a large amount of succulent material, 



106 The Principles of Agronomy 

should be kept fairly moist all the time. If "a soil is deep 
and retentive, a few heavy irrigations are usually better 
than many light ones ; but, on a shallow, sandy soil, 
it is necessary to apply water often. Deep-rooted crops 
can go without water much longer than those keeping 
their roots near the surface. 

Under irrigation, it is a good thing for a farmer to have 
a number of crops in order that the water may be used 
on one when the other does not need it. When but one 
crop is grown, it may require the irrigation stream for 
only a small part of the season, leaving the water to waste 
at other times; hence, a larger area can be served by a 
given stream of water if it is used on a number of crops. 

109. Over-irrigation. — The farmer who irrigates every 
time he gets a chance whether his land nee^s it or not is as 
bad as the boy who went to the theater every night and 
slept during the performance. On being asked why he 
attended, if he was not sufficiently interested to stay 
awake, he replied that he had to go because he had a 
season ticket. 

To irrigate when not necessary is a waste of time and 
water, both of which are precious. Too much water 
reduces actual yields, and, in addition, ruins the land by 
washing out fertility. It would not be so bad if the 
offender alone had to suffer, but his folly causes injury 
to his neighbor located on lower land by water-logging 
the soil and causing alkali to rise. There should be laws 
to prevent the excessive use of irrigation water. 

110. Need for economy. — There is very much more 
land in arid regions than can be served by the available 
water; hence, the factor limiting crop production is not 
land, but water. It is important, therefore, from the 
standpoint of the community, that all water be used to 
the best advantage. Six acre-feet of water will produce 



The Control of Soil Water 



107 



many times as much if applied to five or six acres of land 
as it will if applied to one. As the available water be- 
comes less plentiful, methods of greater economy will be 
introduced. These will be of benefit to the individual 
farmer, as well as to the general community. Economy 
in water distribution (note Fig. 26) becomes a prime 
requisite. 

DRAINAGE 

111. Removing excessive water. — There are many 
million acres of land in the United States containing so 








Fig. 27. — Machine for digging drainage ditches. 



much water that crops cannot be successfully raised there. 
Part of this land is in permanent swamps, while some of it 
is dry during a portion of the year, being water-logged 
only at certain seasons. There is also much land having 
a fairly dry surface appearance, but with ground water 
so near that roots cannot penetrate to any great depth. 



108 



The Principles of Agronomy 



The chief difficulty in the way of successful agriculture 
on all such fields is the surplus water. The only way to 
make them suitable for crops is to drain them. Drainage 
practices are shown in Figs. 27 to 29. 

112. Removing alkali. — In most arid regions, much of 
the land contains a high percentage of soluble salts. This 
often accumulates in such large quantities that the growth 
of plants is prevented. Drainage is the only method of 
permanently removing the alkali, which is gradually 




Fig. 28. — • Drainiiie an orchard. 



carried away by percolating waters. Much of the land 
that is at present valueless, on account of its high alkali 
content, would be of excellent quality if its excess salts 
were removed. 

113. Benefits of drainage. — The drainage of wet land 
improves it, in many indirect, as well as direct, ways. 
Lowering the water-table gives plants a larger zone from 
which their roots can draw plant-food and moisture. 
This lessens the need of fertilizers and the susceptibility 
to drouth. The increased aeration of the soil resulting 



The Control of Soil Water 



109 



from drainage promotes the growth of desirable organisms, 
increases favorable chemical action, and makes the soil a 
much more desirable home for plants. It warms the 
soil earlier in the spring, thereby increasing the growing- 
season of crops. 

Drainage improves the sanitary conditions of a region 
by drying the breeding places of disease germs and 
disease-carrying insects. It lessens the winter-killing of 









fesu "■ ■■ "'^^ 




. 'Jl ^ 


M . '^ 




^•••'^^^Ci.J'iiitllii'i^ 


. >4 





Fig. 29. — Drainage outlet that is likely to clog. 



crops by reducing heaving of the soil ; and it very de- 
cidedly improves structure and tilth. All of these 
benefits working together result in a good net profit in 
almost every case where drainage is properly done. It is 
a common experience that when twelve or fifteen dollars 
an acre are spent in drainage, the value of the land is 
increased from twenty-five to fifty dollars. 

114. Kinds of drainage. — Any one method of drainage 
is not suited to all conditions, nor is it always practicable 
to employ the method that might seem best. The entire 



110 The Principles of Agronomy 

set of conditions must be taken into consideration before 
deciding just how to drain a piece of land. 

Open ditches are probably the cheapest method of 
carrying away the water. They are used to advantage 
in draining ponds and other surface accumulations. The 
chief advantages of the open drain are, (1) the cheapness 
with which it can be constructed, and (2) the ease 
with which it can be cleaned. Some disadvantages are 
that it renders waste the land occupied, and cuts the 
land area into small fields that are difficult to get at. 
The open ditches become filled with falling earth and 
weeds and are a source of constant danger to farm animals. 

Some form of covered drain is usually preferable for 
ordinary purposes. With the covered drain, a trench 
is dug and some material placed in the bottom that will 
allow water to pass through. This is later covered with 
earth. Some of the materials used for such drains are 
rock, brush, lumber, clay tile, and cement tile. The 
last two are, by far, the most common. Where tile can 
be had, it is recommended under almost all circum- 
stances. 

115. Installing the drains. — The first step in draining 
land is to lay out the system. Some kind of instrument 
for getting levels must be used in determining the con- 
tours and deciding where to place the drain lines, A 
level is also necessary to find the proper depth for the 
trenches. After the system is laid out, the ditches are 
dug either by hand or by machinery. In early days, they 
were practically always dug by hand, but modern machin- 
ery, where it can be had, now does the work much more 
cheaply. Tile should probably not be placed nearer the 
surface than two feet, or farther than five or six feet 
except in unusual cases. Usually about four feet is a 
good depth. 



The Control of Soil Water 111 

The bottom of the ditch should have an even grade, 
otherwise the flow of drainage water will be uneven and 
silt will be deposited in low places. In certain sections, 
where there is a tendency for roots to clog the drains, 
they must be placed deeper than would otherwise be 
necessary. Care should be taken to have the joints of 
the tile fit well together to avoid filling with dirt. The 
work of covering can usually be done with a team. The 
outlet should be screened to keep out small water-loving 
animals, and should be so constructed that it will not be 
easily clogged. 

DRY-FARMING 

116. Scope of dry-farming. — More than half of the 
land surface of the earth receives less than twenty inches 
of annual precipitation. Consequently, this vast area 
is handicapped in its crop production by a shortage of 
moisture. A relatively small part of this total area can 
be reclaimed by the use of irrigation water ; but the 
greater part of it, if tilled at all, must have applied to it 
every possible method of water conservation. The raising 
of crops without irrigation where there is less than about 
tw^enty inches of annual rainfall, has come to be called 
dry-farming. It does not differ essentially from any 
other farming, except that every process is directed 
toward utilizing economically all of the available 
moisture. 

117. The question of rainfall. — The total amount of 
rainfall is not the only consideration. Its distribution 
throughout the year, the quantity falling at one time, 
and the evaporation all modify its effectiveness. In 
some regions with a comparatively high total precipita- 
tion, most of the water falls in the autumn after the crops 
are harvested. A large percentage of this is lost before 



112 



The Principles of Agronomy 



the next summer when it is needed. In other places the 
rain comes in great torrents at a few times during the 
year. In such cases comparatively little of the moisture 
sinks into the soil ; most of it runs off. The intensity of 
evaporation is also important, since it so greatly modifies 

the soil moisture. Hot 
regions, with many 
clear, windy days, chal- 
lenge man's best effort. 
It is difficult to store 
water in the soil from 
w^hich several times 
the total rainfall would 
evaporate. If, how- 
ever, there is but little 
wind and, at the same 
time, a high humidity 
of the air, the loss 
by evaporation is rela- 
tively low. 

Twelve inches of pre- 
cipitation, well distrib- 
uted in a region of 
low evaporation, would 
doubtless make dry- 
farming more success- 
ful than twenty inches 
falling in such a way that most of it is lost. 

The dry-farming areas of the United States are some- 
times divided into the following five areas according to 
the seasonal distribution of rainfall : 

(1) Pacific type, which extends west of the Sierra 
Nevada and Cascade ranges receiving most of its rainfall 
from October to March with but little during the summer ; 




Fig. 30. — A deep, uniform soil, well 
adapted to dry-farming. 



The Control of Soil Water 



113 



(2) Sub-Pacific type, which extends over Utah, Nevada, 
and eastern Washington, having a high winter and spring 
rainfall ; 

(3) Arizona type, which prevails over Arizona, New 
Mexico, and a small part of Utah and Nevada, having 
least rainfall in early summer and most during July 
and August ; 




Fig. 31. — Clearing dry-farm land of brush. 



(4) The Northern Rocky Mountain and Eastern Foot- 
hills type, with the main part of the rainfall coming dur- 
ing the late spring ; 

(5) The Plains type, with most of the rain falling during 
May, June, and July. 

118. Dry-farm soils. — In dry-farming, the soil must 
constantly be used as a reservoir for moisture ; hence, the 
necessity for a soil with high water-holding capacity. A 
soil that is shallow is entirely useless for a dry-farm, 
since it cannot hold sufficient water to supply crops 
between rains. A soil with coarse texture, like sand, is 
not able to hold more than a small quantity of moisture ; 



114 



The Principles of Agronomy 



hence, it cannot be used in dry-farming. The ideal dry- 
farm soil is at least eight or ten feet deep and loamy. It 




Fig. 32. — Plowing stubble on a dry-farm. 

should be easily tilled and readily mulched. A good type 
of soil for dry-farming is shown in Fig. 30. 




Fiu. 33 — A large niulclung unijituKut u-^td m diy-farnung 



TIw Control of Soil Water 



115 



119. Dry-farm crops. — No set rule can be given for 
the best crops to be grown on the dry-farm. The problem 
must be worked out for each climatic and soil condition. 
Up to the present, however, the cereals have been most 
widely as well as most successfully grown. Of these, 




Fig. 34. — • The amount of moisture which the plant has affects the 
proportion of different parts. 



wheat is king. In regions where the major part of the 
precipitation comes during the winter, fall wheat has done 
best ; but where the rain falls during the summer or 
where winter-killing is severe, the spring-planted varieties 



116 



TJw Principles of Agronomy 



have been most successful. Barley, oats, emmer, and 
rye have been raised with varying success depending on 
conditions. In hot climates, the grain-sorghums have 
become important dry-farm crops. Corn has been 
successful over a wide range of conditions, and has the 
advantage of being planted in rows, which permits it to 
be cultivated during growth. 

It has been difficult, up to the present, to find forage 
crops that grow well under extreme drouth. Alfalfa, 




Fig. 35 



Experiments to determine the amount ol waier ii^scd by 
crops. (Utah Experiment Station.) 



field peas, and smooth brome-grass have been used to 
some extent. Potatoes and a number of vegetables have 
done well. Trees for shade and fruit are grown in some 
sections, but usually it is difficult to get them started. 

120. Tillage methods. — Though the same tillage 
methods are not successful in all dry-farm areas, most of 
the fundamental principles hold for all conditions. The 
objects of tillage are to make the land receptive to rain 
and to prevent loss after the moisture is once in the soil. 

Deep plowing, usually in the fall, and considerable 



The Control of Soil Water 117 

subsequent tillage have been found best to accomplish 
this end. Thin seeding is almost always practiced on 
such farms. Every precaution must be taken to prevent 
the growth of weeds, as they consume the moisture needed 
by crops, in addition to being in the way at harvest and 
reducing the value of the crops. Over the greater part 
of the dry-farm region, summer fallowing is a successful 
practice. It makes possible the use of two years' pre- 
cipitation in the production of a single crop and aids 
greatly in the control of weeds. The great amount of 
tillage required in dry-farming has made necessary the 
development of special machinery which can utilize a 
relatively large amount of poM'er. Clearing and village 
operations on dry- farms are shown in Figs. 31 to 33. 
The effects of irrigation are graphically shown in Figs. 
34 and 35. 

SUPPLEMENTARY READING 

Principles of Irrigation Practice, J. A. Widtsoe. 

Irrigation and Drainage, F. H. King. 

Irrigation, F. H. Newell. 

Irrigation Institutions, Elwood Mead. 

Working Data for Irrigation Engineers, E. A. Moritz. 

Use of Water in Irrigation, Samuel Fortier. 

Practical Irrigation and Pumping, B. P. Fleming. 

Practical Farm Drainage, C. G. Elliott. 

Dry-Farming, J. A. Widtsoe. 

Dry-Farming, Thomas Shaw. 

Soil Cultiu-e Manual, H. W. Campbell. 

Cyclopedia of American Agricultiu-e, Vol. I, pp. 412-440. 

Physics of Agriculture, F. H. King, pp. 286-328. 

U. S. D. A. Farmers' Bulletins : 

No. 138. Irrigation in Field and Garden. 

263. Practical Information for Beginners in Irrigation. 

266. Management of Soils to Conserve Moisture. 

371. Drainage of Irrigated Lands. 

399. Irrigation of Grain. 

524. Tile Drainage on the Farm. 



CHAPTER XI 

PLANT-FOOD OF THE SOIL 

The method by which plants secure their food from the 
soil was not discovered until comparatively a few years 
ago. From the time of the ancient Greeks and Romans 
down to the beginning of the nineteenth century, investi- 
gators sought to find some one substance in the soil that 
was the real food of plants. At different times it was 
thought to be fire, water, nitre, oil, and many other 
materials ; and the idea was rather generally held that 
plants fed on a single substance. During this period all 
plant-food was supposed to come from the soil ; it was 
not known that the greater part comes from the air. One 
theory that was held for a long time was that humus, or 
organic matter, furnished the material from which growing 
plants secured their food. After it became known that 
the carbon of plants is derived from the carbon dioxide 
gas in the air and that only ash comes from the soil, it 
was easy to find the real function of the soil and how to 
control its plant-food. 

121. What plants use from the soil. — Of the ten ele- 
ments required by plants seven, in addition to those 
obtained from water, come from the soil. These are 
potassium, phosphorus, calcium, magnesium, iron, sulfur, 
and nitrogen. A number of non-essential elements, 
including sodium, chlorine, and silicon,* are also taken up 
by most plants. Elements are not used by plants in 

118 



Plant-food of the Soil 119 

their elementary condition, but they are taken from the 
soil minerals, each of which is made up of a number of 
elements. All crops require the same elements for their 
growth, although they do not all use them in the same 
proportion. Potatoes and sugar-beets use relatively 
large quantities of potassium, the grain crops require 
considerable phosphorus, while alfalfa and clover use more 
calcium than do most other crops. This is one, but only 
one, of the reasons for practicing rotation. 

Water, which furnishes the elements oxygen and 
hydrogen, is also taken from the soil. Only a small 
quantity of water would be required if its sole function 
were to furnish these elements, but it is used as a carrier 
of foods in the plant and is also transpired in large quanti- 
ties ; hence, the quantity used by crops is much greater 
than that of all the other foods combined. The method 
of supplying and conserving the soil moisture has been 
discussed in Chapter X. 

122, Composition of soils. — Soils are made up largely 
of insoluble material of no food value for plants. The 
amount of actual plant-food in the soil is comparatively 
small, but since plants do not use large quantities of this 
food, the supply is sufficient for crop production. Hil- 
gard has compiled in the following table a great number 
of analyses of typical soils. 

These analyses show that less than 5 per cent of humid 
soils is composed of plant-food and that the remainder is 
largely made up of material insoluble even in strong 
acid. In arid soils, the proportion of plant-food is some- 
what higher, but even there, it comprises less than 10 
per cent of the total soil. 

The organic matter in humid soils is usually much higher 
than that in soils of arid regions ; but the low organic 
matter of the arid soils is relatively high in nitrogen. 



120 



The Principles of Agronomy 



Table 1. — Chemical Composition of Humid and Arid 
Soils. Strong Hydrochloric Acid Analysis 





Humid Regions 


Arid Regions 




Average op 696 


Average of 573 




Samples 


Samples 


1. Insoluble residue .... 


84.17 


69.16 


2. Soluble silica (SiOo) 




4.04 


6.71 


3. Alumina (AI2O3) . . . 




3.66 


7.21 


4. Ferric iron (FcoOs) . . 




3.88 


5.48 


5. Sulfuric trioxide (SO 3) . 




0.05 


0.06 


6. Manganese (MnOo) 




0.13 


0.11 


7. Phosphoric acid (P2O5) 




0.12 


0.16 


8. Lime (CaO) .... 




0.13 


0.43 


9. Magnesia (MgO) . . . 




0.29 


1.27 


10. Soda (NaoO) .... 




0.14 


0.35 


11. Potash (K2O) .... 




0.21 


0.67 


12. Humus 




1.22 


1.13 



123. The analysis of soils. — In order to determine 
the plant-food in a soil, the chemist takes a sample to a 
laboratory, where he analyzes it. He does the sampling 
very carefully, since the accuracy of the analysis depends 
on the accuracy of the samples. If, for example, he 
should analyze just the surface inch, his results would not 
apply to the lower depths of the soil where roots often 
feed ; frequently the soil varies much in composition at 
these different depths. Again, if the sample should be 
taken from a low place containing considerable organic 
matter, it would not represent the entire field. In sam- 
pling, therefore, the chemist takes soil from a number of 
places in the field and at various depths and mixes all 
together in order to get an average sample for analysis. 

After the sample has been prepared, the method of 
analysis depends on the information desired. If the total 



Plant-food of the Soil 121 

plant-food is to be determined, the soil is treated with 
certain acids which dissolve the soluble matter, after 
which the chemist can determine the quantity of the 
various elements in it. 

124. Available and reserve plant-food. — Only a small 
part of the total plant-food of the soil is available to 
crops during any one year. Roots penetrate every part 
of the soil, but they can absorb only material that is in 
solution. Through the carbon dioxide which they give 
off, the roots assist in dissolving the minerals of the soil. 
Their action is slow, consequently only a small portion of 
each compound can be used in any one year. This is 
very fortunate, since, if all plant-food were readily dis- 
solved, it would be leached out by rains or floods. The 
potassium found in such minerals as mica becomes avail- 
able only after years of weathering, while that in kainit 
can be immediately dissolved. It is impossible, there- 
fore, from a chemical analysis, to tell how much of a given 
element is available to plants for immediate use without 
knowing in what minerals it is contained. 

125. Making plant-food available. — The making avail- 
able of reserve plant-foods as fast as needed by crops is 
one of the chief problems of soil management. This is 
done (1) by tillage, which aids weathering agencies in 
their action on soil particles ; (2) by drainage, which 
allows air to circulate more freely through the soil ; (3) 
by plowing under organic matter, which, in decaying, 
helps to make the minerals soluble ; and (4) by numerous 
other less important means. The nitrogen present in 
the soil is made available by nitrification, which is favored 
by tillage and by a desirable moisture content. 

126. Quantity of plant-food removed by plants. — 
Each crop uses plant-food in varying quantities. The 
quantity of mineral foods taken from the soil by different 



122 



The Principles of Agronomy 



crops is expressed by Warington in the following table, which 
includes the material found in the entire harvested crop. 

Table 2. Mineral Foods removed from the 
Soil by Crops 



Total 



Crop 



Wheat . . 
Barley . . 
Oats 

Maize . . 
Meadow hay 
Red clover 
Potatoes 
Turnips 



Yield 


Ash 


Nitrogen 


Potash 


Lime 


30 bu. 


172 lb. 


48 1b. 


28.8 lb. 


9.2 lb. 


40 bu. 


157 lb. 


48 1b. 


35.7 lb. 


9.2 lb. 


45 bu. 


191 lb. 


55 1b. 


46.1 lb. 


11.6 lb. 


30 bu. 


121 lb. 


43 lb. 


36.3 lb. 




U T. 


203 lb. 


49 lb. 


50.9 lb. 


32.1 lb. 


2T. 


258 lb. 


102 lb. 


83.4 lb. 


90.1 lb. 


6T. 


127 lb. 


47 1b. 


76.5 lb. 


3.4 lb. 


17 T. 


364 lb. 


192 lb. 


148.8 lb. 


74.0 lb. 



Phosphoric 
Acid 



21.1 lb. 
20.7 lb. 

19.4 lb. 

18.0 lb. 
12.3 lb. 
24.9 lb. 

21.5 lb. 

33.1 lb. 



The table shows the variation in the relative quantities 
of nitrogen, potash, lime, and phosphoric acid used by 
different crops. 

127. Plant-foods that are scarce. — Of the ten ele- 
ments required by plants, only three may be considered 
as scarce. These are nitrogen, phosphorus, and potas- 
sium. In a few soils calcium and sulfur may be deficient, 
but they are usually present in sufficient quantities to 
supply the needs of crops for centuries. 

Nitrogen is, without doubt, the element most likely to 
be lacking in soils, and it is the most expensive element 
when purchased ; but the fact that it can be added to 
the soil by the growth of leguminous plants makes its 
maintenance possible in every soil. Phosphorus, which 
is used in large quantities by the grain crops, is present 
in exceedingly small quantities in many soils. On this 
account, it becomes necessary to use phosphorus fertilizers 



I 



Plant-food of the Soil 123 

in order to maintain the fertility of these soils. Potas- 
sium is usually present in fairly large quantities, but 
since it is, in the main, not available to plants, soils usually 
respond to potassium fertilizers. It is probable, however, 
that proper methods of increasing the availability of 
reserve potassium will do much toward making unneces- 
sary the heavy use of this fertilizer. 

128. Exhaustion of the soil. — The possible exhaus- 
tion of the soil has been discussed for many years; 
numerous different opinions have been held. Some have 
contended that the plant-food supply is rapidly being 
used up and that it will not be long before the soil is so 
impoverished that crops will not grow. Others have 
maintained that the soil is being constantly renewed and 
as a result will never be exhausted. Experience has 
demonstrated, however, that, if the productivity of the 
soil is to be maintained at a high standard, part of the 
plant-food removed by crops must be returned either as 
farm manure or as commercial fertilizers. Since plant- 
food is rendered^ available but slowly, it is probable that 
crops never can entirely exliaust the soil. A lessened 
supply of available food, however, greatly reduces yields 
of all crops. 

129. Losses in plant-food result primarily from the 
removal of crops from the land, but in regions of heavy 
rainfall large quantities are also removed by leaching and 
by surface washing. In some of the limestone areas of 
the eastern part of the United States, the rock and soil 
have been leached so much that the greater part of the 
original material has been removed, leaving only the more 
insoluble minerals. Naturally, during this process the 
more available compounds have been carried away. In 
many sections, surface erosion is responsible for the 
destruction of much valuable land. The soil is, in some 



124 The Principles of Agronomy 

cases, washed entirely away, while in others, the main 
part is retained, but the soluble material is leached from 
the surface. 

130. Plant-food in organic matter. — The organic 
matter of the soil is composed almost entirely of dead 
plants in various stages of decomposition. These dead 
tissues contain a quantity of mineral matter that has 
been once in solution, and is, therefore, more likely to 
be available to growing plants than the minerals. Nitro- 
gen is particularly important in this connection, since 
practically all of the nitrogen of the soil is found in the 
organic matter. Besides furnishing directly a part of the 
plant-food, organic matter assists, by its decay, in render- 
ing available the mineral matter of the soil. 

131. Relation of plant-food to value of a soil. — In 
order that a soil may be valuable, it must have an ample 
supply of plant-food ; but this is by no means the only 
consideration. Farmers sometimes submit a small sample 
of soil to a chemist with the request that he analyze it 
and tell what the land is worth. Those who are familiar 
with soil study understand that it is impossible by merely 
knowing the total quantity of plant-food to tell the exact 
value of any land. Such questions as drainage, aeration, 
mositure supply, texture, and many other things help 
to determine what a soil can produce. All these factors 
must be taken into consideration in estimating the value 
of land and in outlining methods of management. 

SUPPLEMENTARY READING 

Soils, Lyon, Pippin, and Buckman, pp. 327-374. 

Fertilizers and Crops, L. L. Van Slyke, pp. 105-116. 

The Soil, F. H. King, pp. 107-134. 

Soils, E. W. Hilgard, pp. 313-421. 

Physics of Agriculture, F. H. King, pp. 69-106. 

First Principles of Soil Fertility, A. Vivian, pp. 3-46. 



CHAPTER XII 
MANURES AND FERTILIZERS 

Plants require for tlieir growth an available supply 
of various mineral foods. These shoukl be present in 
the soil in a balanced condition in order that the plants 
may find the most congenial environment. Crop yields 
are decreased if any one of these necessary elements is 
present in exceptionally small quantities. Even if all 
other conditions are favorable, the producing power of 
most soils could be materially increased by simply chang- 
ing the available supply of one or two elements. The 
addition of a fertilizer may effect this readjustment. 

Where crops are raised continuously on land and re- 
moved each year, a certain amount of plant-food is carried 
away. An unreplenished deposit of money in the bank, 
no matter how large, will in time be exhausted if contin- 
ually drawn out. The plant-foods in the soil may be 
considered in much the same way, and wliile this analogy 
is not entirely true, yet the same principle holds. 

Some soils contain a very great store of plant-food, but 
even such will not continue to endure abuse without 
protesting by giving reduced yields. If a permanent 
system of agriculture is to be maintained on any soil, 
no matter how rich, at least a part of the mineral matter 
that is removed must be returned either in the form of 
farm manure or commercial fertilizers. 

125 



126 The Principles of Agronomy 

Materials are often applied to the soil for their indirect 
action as well as for the plant-food which they add. 
Farm manure improves the physical condition of the soil ; 
lime corrects acidity and flocculates the particles of fine 
clay ; other fertilizers help to render available the reserve 
store of plant-food in the soil. 

132. Tjrpes of fertilizers. — The materials added to 
the soil either as direct or indirect fertilizers are numer- 
ous. By far the most important of these is farm manure, 
which is composed largely of animal excreta mixed with 
litter. Of the fertilizers purchased from the outside, the 
most common are those applied for the nitrogen, phos- 
phorus, and potassium they contain. These are usually, 
but not always, in the form of mineral salts. Other 
materials called amendments are used for their indirect 
action on the soil rather than for the direct plant-food 
they furnish. In addition to these substances, which 
must be hauled to the soil, it is a common practice to 
grow certain crops which serve a similar purpose. These 
are usually the legumes. In order for them to be of use 
as a fertilizer, they are plowed under. 

133. How to determine fertilizer needs. — In the 
United States, more than one hundred million dollars are 
spent each year for commercial fertilizers in addition 
to the billions of dollars worth of farm manure that is 
used. It is probable that nearly half of this commercial 
fertilizer is wasted on account of lack of judgment in 
applying it. One of the most important problems con- 
nected with the use of fertilizers is to know the needs of 
the soil and to be able to supply these needs in an intelli- 
gent and economical manner. 

This is no simple matter. It is impossible by any 
single means to say just what is the best treatment for a 
soil, but by combining the knowledge of science and the 



Manures and Fertilizers 127 

wisdom of the practical farmer, a partial solution of this 
problem can be reached. A chemical analysis of the soil 
is very useful in determining the needs of soil, but it is 
not sufficient. Such analysis must be compared with 
field tests of fertilizers, and with practical tests of crops 
in order to determine soil needs. Where all this in- 
formation is brought together and carefully studied a 
fairly accurate judgment of the soil requirements can be 
made. The practice of simply applying any kind of 
fertilizer the dealer may have for sale, without making 
a thorough investigation, cannot be too strongly con- 
demned. 

134. Nitrogen fertilizers. — Nitrogen is the most ex- 
pensive of all the fertilizer elements, and the world's 
supply of this compound is limited. Formerly, it was 
obtained from guano, which is manure and decayed bodies 
of birds, but this source of supply is now practically 
exhausted. At present the chief source is the beds of 
sodium nitrate, or Chile saltpeter, found in Chile. It lies 
near the surface of the ground in great beds, but is so 
mixed with rock and earth that leaching out of the salt 
is necessary before it is ready for market. Nitrogen in 
the form of sodium nitrate is directly available to plants. 

Ammonium sulfate is another important source of 
nitrogen. In the making of coal-gas by the distillation of 
coal, a quantity of ammonia is given off. The gas is 
passed through sulfuric acid, where the ammonia is re- 
moved and ammonium sulfate formed. This salt is about 
20 per cent nitrogen. 

It is possible, by means of electricity and in other ways, 
to combine the nitrogen of the air in such a manner that 
it can be used as a fertilizer. The chief products of these 
processes are calcium nitrate and calcium cyanamid. 
The main difficulty in the way of using these fertilizers 



128 The Principles of Agronomy 

more widely is the lack of cheap power which is required 
in the manufacture of them, 

A great many animal products are used, chiefly for 
their nitrogen. Dried blood, dried flesh, ground fish, 
tankage, hoof and horn meal, leather meal, and wool and 
hair waste are all used. The availability of the nitrogen 
in these compounds diminishes about in the order given. 
In dried blood the nitrogen is available at once, while in 
leather and hair it can be used but slowly. 

135. Nitrogen-fixation. — While the use of some com- 
mercial nitrogen may always be necessary, it is probable 
that the best husbandry will direct the farmer to add the 
necessary quantity of nitrogen to his soil by the growth 
of legume crops which are capable, through the nodule- 
forming bacteria on their roots, of fixing the nitrogen of 
the air. Thus, when these crops are plowed under they 
enrich the soil on which they were grown. The details 
of this operation are described at greater length in Chap- 
ter XIII. 

136. Phosphorus fertilizers are obtained from both 
organic and mineral sources. Bones in various forms are 
extensively used. Formerly, they were used chiefly 
in the raw condition, both ground and unground ; but 
now most of the bone is first steamed or burned to remove 
fat and nitrogenous materials which are used for other 
purposes. Fine grinding of bone makes its phosphorus 
more easily available. Tankage that is relatively high 
in bone is used largely for its phosphorus, and if high 
in flesh scraps, it is valuable for its nitrogen. Bone is 
sometimes treated with sulfuric acid to render its phos- 
phorus more available. 

Mineral phosphorus is found in several kinds of rock 
which usually have the phosphoric acid in combination 
with lime, iron, and aluminum. The presence of the 



Manures and Fertilizers 129 

last two elements reduces the availability of phosphorus. 
Rock phosphates are used in various ways. Formerly, 
the rock was practically all treated with sulfuric acid to 
form super-phosphate, or acid-phosphate as it is often 
called ; but of late years, the use of finely-ground raw 
rock-phosphate is increasing, especially on soils rich in 
organic matter. The acid-phosphate is doubtless more 
immediately available than the raw rock, but it is also 
much more expensive. 

In the manufacture of steel from pig-iron, much phos- 
phorus is removed with the slag. This is called Thomas 
slag ; it is often ground and used as fertilizer. 

137. Potassium fertilizers. — Most of the potassium 
fertilizers used in the world come from the Stassfurt 
deposits in Germany. Here, a great many minerals 
containing a high percentage of potassium are found. 
Some of these are ground and put on the land direct, 
while others are leached with water to concentrate them 
before they are used. Kainit and silvinit are among the 
most common of these minerals. 

Wood ashes have, for generations, been known to be 
high in potash. They are often applied directly to the 
land, but they are sometimes leached to obtain the potash 
in a more concentrated form. In some countries where 
there is abundant sunshine, sea water is evaporated and 
potassium obtained by fractional crystallization. Many 
rocks such as orthoclase feldspar and others contain a 
comparatively high percentage of potassium. These 
rocks have sometimes been ground and used as fertilizers, 
but their potassium is so unavailable that their use is of 
doubtful value. 

138. Lime. — Many soils, particularly in humid re- 
gions, have an acid reaction which is not conducive to 
the best growth of most crops. It is necessary to neu- 



130 Tlie Principles of Agronomy 

tralize this acidity before such crops as alfalfa and clover 
will thrive. This is best done by the use of sotne form 
of lime. Burned lime has been used very extensively, 
but it is gradually giving way to finely-ground limestone 
which is much easier to handle. The effectiveness of 
limestone depends to a great extent on the fineness of 
grinding. 

139. Indirect fertilizers. — Many substances are added 
to the soil because of their indirect or stimulating action. 
Among the most common are gypsum, common salt, iron 
sulfate, soot, and manganese salts. While it may be ad- 
visable to use some of these materials for special cases, 
their general use is not recommended, since they add no 
real plant-food and their temporary benefit may have a 
reaction. 

140. Home-mixing of fertilizers. — Many farmers 
would rather pay more for fertilizers that are already 
mixed than to take the trouble of mixing them. This is 
largely because they do not realize how much more they 
have to pay for the various elements when purchased in 
the commercial brands of fertilizers than if obtained as 
the simple fertilizing materials such as sodium nitrate, 
acid-phosphate, and potassium chloride. 

Fertilizer manufacturers possess no special secrets 
that cannot be learned by any farmer who will give the 
subject a little study. It is a poor policy to pay hundreds 
of dollars every year for fertilizers about which nothing 
is known save what is told by the salesman. Better 
economy would lead the farmer to spend a few dollars 
buying books on the subject, as the information obtained 
from one book may make possible the saving of from 25 
to 50 per cent on the fertilizer bill. Any farmer can at 
very little expense prepare a place in which to mix ferti- 
lizers; then, by purchasing the materials best suited to 



Manures and Fertilizers 



131 



his conditions, he can mix them himself and thereby obtain 
a much more effective fertihzer at the same expense. 
Self-rehance in this and other respects is often a great 
advantage. 

141. Value of farm manure. — The use of farm manure 
is the surest means of preserving soil fertihty. Practically 



EFFECT OF MANURE ON PERCENTAGE OF DIFFERENT Pl_ANT RARXS 



ST 

Per fl. 



1ST 

Per fl. 



Fig. 36. — Effect of manure on proportion of different parts of corn plant. 

every farm produces a quantity of this by-product of 
animal husbandry ; and a wise use of it is at the founda- 
tion of permanent agriculture. Since the very dawn of 
history, the excreta of animals have been used as fertilizer. 
For a long time, little was known of the way in which it 
improved the s6il, but the increase which it made in the 



132 The Principles of Agronomy 

yield of crops was very evident. IManure is now known 
to benefit the soil by adding directly a quantity of plant- 
food, by increasing the organic matter, and by aiding the 
work of desirable soil organisms. It may not in all cases 
be a complete and well-balanced fertilizer for every soil, 
but its use can always be recommended with safety. 
INIanures have an effect on the porportion of different parts 



Fig. 37. — Fields used in famous fertilizer experiments. (Penn. Experi- 
ment Station.) 

of the plant (Fig. 36). Fig. 37 shows the way in which a 
field is laid out to test the value of different fertilizers. 
142. Kinds of farm manure. — The manure from each 
kind of farm animal is different. That produced by 
poultry and sheep is concentrated and dry, while that 
produced by cattle and horses contains more water and 
coarse material. The manure of any animal is influenced 
by the kind of food it eats, its age, work, and several 
other factors. Old animals, that do but little work and 
eat much rich food, produce the best manure. 



Manures and Fertilizers 



133 



Liquid manure is richer in plant-food elements than 
the solid, but it lacks the organic matter which is so bene- 
ficial to most soils. Good husbandry requires the saving 
of both the liquid and the solid manure, which can easily 
be kept together if sufficient bedding material is used to 
absorb the liquid. 

143. Losses in manure. — Losses occur in manure by 
leaching and by fermentation (Figs. 38, 39). Experi- 




FiG. 38. — Manure piled where its plant food will be leached. 

ments have shown that, when left carelessly exposed to 
the weather for six months, manure loses about half its 
value. This loss can be overcome in large measure by 
proper methods of storage even without expensive equip- 
ment. The plant-foods contained in manure are readily 
soluble and but little rain is required to dissolve and 
carry them away. If manure is left scattered in an open 
yard, it is wet through by every rain and the greater part 
of its plant-food is washed out before the season is 
over. If manure has to be stored for any length of 



134 



The Principles of Agronomy 



time it should be so piled that it cannot be leached. 
This may be done by putting it under cover or by making 
the pile of proper shape. 

Manure is filled with bacteria and fungi which are 
constantly at work. Some of these tend to make the 
manure heat, causing a loss of considerable nitrogen. 
Since these destructive organisms work best in manure 
that is loose and fairly dry, their action can most easily be 




Fici. 39. — Manure pile in an unsightly and inconvenient place. 

prevented by compacting the manure to exclude air and 
by keeping it moist. 

144. Handling farm manure. — Experience has demon- 
strated that the best way to handle farm manure is to 
haul it out and spread it on the land when fresh. This 
prevents any serious loss from either leaching or fermen- 
tation. ]\Iany farmers haul manure on to the field and 
leave it standing for months in small piles. This is not 
a good practice, since its loose condition allows destructive 
fermentation to go on readily. Moreover, the leaching 



Manvres and Fertilizers 



135 



of the piles causes an irregular distribution of plant-food 
over the field. Fig. 40 shows a common manure carrier. 
During parts of the year there is no vacant land on 
which manure can be spread, and hence it must be stored. 
This can be done in special manure pits, under sheds, or 
in the open yard. Expensive pits probably do not pay, 
but simple devices to assist in handling manure are with- 




FiG. 40. — Manure carriers are becoming almost a farm necessity. 



out doubt a good thing. It has already been stated that 
by proper piling, the loss due to leaching and fermenta- 
tion can be practically overcome. Where an open yard 
is used the neatest and most sanitary kind of pile, as well 
as the one allowing least loss, is a square pile with verti- 
cal sides and with edges slightly higher than the middle. 
The manure that is produced each day should be put on 
the pile and should be kept compact and moist. 



136 The Principles of Agronomy 

A manure spreader is a great time-saver, and makes 
possible a more even distribution than can be made by 
hand. The amount of manure that is a])pHed is usually 
limited by the quantity that can be obtained. Few 
farmers are in danger of over-manuring their land. Most 
soils will use forty or fifty tons to the acre every few years 
without suffering any injury. 

145. How to fertilize different crops. — While each 
crop uses exactly the same plant-food elements, the rela- 
tive quantities used by different crops vary. Potatoes 
and sugar-beets use relatively large quantities of potas- 
sium ; the grain crops require considerable phosphorus ; 
while the legumes use relatively more lime and nitrogen. 
Each crop also has different rooting habits. These facts 
must all be taken into consideration when applying ferti- 
lizers. In pastures an early growth of succulent forage is 
desired. This calls for the application of some form of 
available nitrogen. The needs of each crop and the 
quality of product desired should be carefully studied 
before deciding just how to fertilize. It is, of course, 
necessary to have the fertilizer conform to the needs of 
the soil. 

146. Green manures. — The plowing under of grow- 
ing plants to increase the organic content of the soil has 
been practiced for centuries. The decay of these plants 
helps to make available the mineral foods of the soil, 
and helps to correct defects that exist in its physical 
nature. 

Legumes make the best green-manure crops, since they 
increase the nitrogen supply of the soil by taking this ele- 
ment from the air and combining it in such a way that it 
can be used by other plants. The clovers, vetches, cow- 
peas, soybeans, field peas, and alfalfa are all plowed under 
as green manures. The small-grains are also much used 



Manures and Fertilizers 137 

for this purpose. A worn-out or poor soil will usually 
produce a fair growth of rye which, when plowed under, 
puts the soil in a condition to raise other crops. 

In arid regions where water is scarce, the use of green- 
manure crops is somewhat limited ; but in humid climates, 
especially where soil erosion has to be contended with, 
green-manure crops are necessary in building up the soil. 
It is often possible to raise a fairly good green-manure 
crop after the regular crop is harvested. 



SUPPLEMENTARY READING 

Fertilizers and Crops, L. L. \'an Slyke. 
Manures and Fertilizers, H. J. Wheeler. 
Farm Manures, C. E. Thome. 

First Principles of Soil Fertility, A. Vivian, pp. 113-260. 
Crops and Methods of Soil Improvement, A. Agee, pp. 159-1S9. 
Soils and Fertilizers, H. Snyder, pp. 131-159. 
Cyclopedia of American Agriculture, Vol. I, pp. 456-513. 
Fertilizers, E. B. Voorhees. 
Fertilizers and Manures, A. D. Hall. 
The Fertility of the Land, I. P. Roberts, pp. 131-355. 
Soils, Lyon, Fippin, and Buckman, pp. 4S9-626. 
Soil Fertility and Permanent Agriculture, C. G. Hopkins, pp. 517-548. 
U. S. D. A. Farmers' Bulletins : 
No. 44. Commercial Fertilizers. 
77. The Liming of Soils. 

192. Barnyard Manure. 

245. Renovation of Worn-out Soils. 

278. Leguminous Crops for Green Manuring. 

286. Comparative Value of Whole Cotton Seed and Cotton 
Seed Meal in Fertilizing Cotton. 

342. Conservation of Soil Resources. ■ 

398. Farm Practice in the use of Commercial Fertilizers in 
the South Atlantic States. 

406. Soil Conservation. 



CHAPTER XIII 
ORGANISMS OF THE SOIL 

The soil is not a mass of dead matter, but is filled with 
living organisms which are constantly transforming its 
compounds and renewing its productiveness. These 
organisms work on the dead bodies of plants and animals 
and make the materials composing them useful to growing 
plants. All life on the earth is dependent for its continu- 
ance on the unseen organisms which swarm in the soil. 
If it were not for their renewing action, the available 
plant-food would in time be consumed and plant growth 
would cease. A soil composed merely of dead mineral 
matter unable to support life would be valueless. For- 
tunately, the soil is not in this condition, but teems with 
myriads of microscopic organisms of many forms, each 
contributing its share toward making the soil productive. 

147. Kinds of soil organisms. — A great diversity of 
life exists in the soil. Animals, such as squirrels and 
gophers, burrow in the ground and are important in 
mixing the soil. Earth-worms are continually making 
the soil more mellow by mixing mineral and organic 
matter and by increasing the availability of many of the 
plant-foods. Their work is particularly important in 
heavy, wet soils, where they improve aeration. The 
higher plants increase the circulation of air and add or- 
ganic matter by sending their roots into every part of the 
soil; certain of the higher fungi assist in the decay of 

138 



Organisms of the Soil 139 

organic matter ; and last, but not least, come the bacteria, 
which are the most important of all the soil organisms 
in the influence they exert. 

148. Bacteria. — The existence of bacteria was dis- 
covered by Leeuwenhoek in 1695, but little was known 
of their real nature until a few years ago. They belong 
to the plant kingdom, and are composed of single cells 
about 2 5 o^ ^^^ ^^^^^^ ^^^ diameter, although they vary 
considerably in size as well as shape. Increase is rapid, 
since under favorable conditions one may divide in about 
a half hour. At this rate, the number that might be 
produced from a single individual in a week is almost 
beyond computation. Bacteria cause many of the com- 
mon diseases of animals and plants. The discovery of 
this fact made possible a new era in the treatment of 
disease. All bacteria are by no means harmful ; some 
seem to be neutral in their action ; others are decidedly 
beneficial. Most soil organisms are helpful in one way or 
another. 

149. The number of bacteria in the soil is probably 
about as large as can be supported under existing condi- 
tions. Desert soils low in organic matter, water-logged 
soils, and sandy soils have comparatively few bacteria ; 
while loamy soils, especially if manured, have many. 
Cultivated soils of the ordinary type usually have from 
1,000,000 to 10,000,000 bacteria in each gram of soil. 
Where conditions are exceptionally favorable the num- 
ber often runs as high as 100,000,000 to the gram ; how- 
ever, this varies greatly during the different seasons of 
the year, and is affected by soil moisture, crops, tempera- 
ture, organic matter, and a number of other factors. 

150. Kinds of bacteria. — The size and shape of bac- 
teria vary greatly. They are classified as spherical, 
cylindrical, and spiral and are often compared in form 



140 The Principles of Agronomy 

with billiard balls, lead pencils, and corkscrews. They 
may occur singly or in aggregates of two or more. The 
spherical forms differ from the others in being able to 
multiply in a number of planes; hence they may make 
chains, flat layers, or cubical masses. The rod-shaped 
and spiral-shaped forms increase in but one direction ; 
they elongate and separate into two parts. The three 
main types are not always distinct, and some forms are 
intermediate. Hair-like flagella borne by some bacteria 
aid in locomotion. 

151. How bacteria grow. — The fact that bacteria 
are colorless makes them unable to use the energy of sun- 
light ; but they, like animals, must depend on the decom- 
position of organic foods for a source of energy. Organic 
material, therefore, is commonly needed for food. Sapro- 
phytic forms obtain their foods from dead plant and 
animal bodies, while parasitic forms get their food from 
living plants and animals. A few forms can live without 
organic matter but subsist entirely on mineral matter. 

Oxygen is needed by most bacteria for their growth ; 
others can grow either in the presence or in the absence 
of oxygen ; still others grow only in the absence of free 
oxygen. None of the higher plants or animals have the 
ability to live without free oxygen. 

Bacteria respond to temperature changes in much the 
same way as do other living things. At very low tempera- 
tures their activities cease, while at very high tempera- 
tures they are killed. The temperature of best growth 
varies greatly with the species. Some grow best at about 
70° F., while many prefer 95° F., and a few species re- 
quire as high as 140° F. for their most rapid growth. At 
a temperature of 160° F. most bacteria are quickly killed, 
although spores of bacteria will often live after being 
heated for a short time at 212° F. 



Organisvis of the Soil 141 

The proper amount and balance of food is one of the 
most important considerations. Sohible carbohydrates 
are used by many for food. Their own products are 
usually detrimental and must be removed or growth 
ceases and death may result. 

152. Relation to humus formation. — Tillage ventilates 
the soil, thus removing these excretions. Practically 
all plant residues eventually find their way into the soil, 
where they undergo changes of some kind. They may 
decay entirely and, with the exception of a small quantity 
of mineral matter, become gas which passes into the 
air; they may undergo transformations resulting in 
the formation of humus in the soil ; or they may remain 
preserved in almost their original form. The greater 
part of the organic matter that gets into the soil under- 
goes some process of humification, and as a result, it is 
of great benefit. 

The changes occurring in the organic matter of the 
soil are largely the result of bacterial action. Some fungi 
begin the decay of woody matter, but the decomposition 
is completed by bacteria. The carbon of the organic 
matter, by its decay and iniion with oxygen in the forma- 
tion of carbon dioxide, furnishes food energy to the micro- 
organisms. In addition to carbon dioxide, many other 
compounds are formed, some of them being rather com- 
plex. Many of the compounds resulting from organic 
decay act as solvents in making mineral matter more 
available to growing plants. The himius remaining in 
the soil as a result of decay is usually lower in carbon and 
higher in nitrogen than the plant residues from which it 
was formed. This is particularly the case in arid climates 
where decay has gone on with but small quantities of 
moisture. 

153. Relation to nitrogen. — Of all the plant-food 



142 The Principles of Agronomy 

elements of the soil, nitrogen is probably the one needing 
most attention. It must constantly be worked over and 
changed from one form to another. A part is lost from 
the soil as free nitrogen and ammonia, which escape into 
the air, or as soluble nitrogen salts which are leached out. 
To prevent these losses and maintain in the soil a supply 
sufficient for the needs of crops, is one of the greatest 
problems of agriculture. 

The atmosphere contains a vast store of nitrogen, but 
this is in an uncombined form and is, therefore, not in a 
condition to be used by plants. The supply of combined 
nitrogen in the soil, on the other hand, is limited. It was 
thought for some time that, on account of losses which 
occurred, this supply would in time be entirely exhausted 
and that it would eventually be impossible to raise crops. 
This was before the action of bacteria was understood. 
We now know that, under proper conditions, these or- 
ganisms are able to combine the nitrogen of the air with 
other elements in such a way that it can be used by plants. 
The discovery of this process known as nitrogen-fixation 
is responsible for a change of ideas regarding soil fer- 
tility. 

Other kinds of bacteria are able to change the nitrogen 
contained in dead animal and plant bodies into a form 
that can be used by living plants. This general process 
which takes place in a number of distinct stages is known 
as nitrification. When available forms of nitrogen, 
like the nitrates, are transformed into non-available 
ammonia or free nitrogen the process is known as denitri- 
fication. 

154. The fixation of nitrogen was first found to occur 
in connection with little nodules which are found on the 
roots of legumes such as peas, beans, alfalfa, and clover. 
It was observed that where these plants grew, the nitrogen 



Organisms of the Soil 143 

content of the soil was increased. Investigation showed 
that the nodules were caused by bacteria working on 
the roots. The bacteria living in these nodules are able 
to use free nitrogen of the air and combine it into the 
organic compounds of their bodies from which it may later 
become available to the higher plants. The fixation of 
nitrogen in connection with the growth of legumes makes 
these plants desirable in all crop rotations. They make 
it possible to maintain the soil nitrogen. It was later 
found that certain bacteria and fungi working independ- 
ently of plants are also able to fix nitrogen from the supply 
in the air. The quantity of nitrogen they fix in the soil 
is large in some cases, though fixation by means of legumes 
proceeds more rapidly. 

155. Nitrification and denitrification. — Most of the 
soil nitrogen has once been held in plants where it was 
one of the important constituents of protoplasm. When 
plants die, their nitrogen returns to the soil as complex 
protein compounds and, as such, it cannot again be used 
until the compounds are broken down. Some bacteria 
and fungi attack dead plants and cause decay, during 
which at least a part of the nitrogen is con\'erted into 
ammonia compounds. Ammonia is then attacked by a 
group of nitrous bacteria which change the nitrogen into 
nitrites, which are in turn con\'erted into nitrates by the 
nitric bacteria. In the form of nitrates, the nitrogen is 
again available to crops. Thus the nitrogen cycle is 
carried on by a number of different forms of organisms. 

In this cycle, nitrogen is taken up as nitrates by the 
higher plants. In their bodies it becomes a part of the 
complex protein compounds. When the plant dies, these 
compounds are broken down into ammonia, which by 
the process of nitrification, is converted into nitrites 
and finally into nitrates, when it is again ready to be 



144 The Principles of Agronomy 

used. Nitrification requires a good supply of oxygen, a 
proper amount of soil moisture, a favorable temperature, 
and a number of other conditions. 

In the soil there are denitrifying organisms which 
change the nitrates back into nitrites and ammonia. 
These work in conditions just the opposite to those favor- 
able for the nitrifying bacteria. Poor drainage and a 
lack of soil air are among the conditions favoring their 
action. In ordinary well-tilled soils these nitrate de- 
stroying organisms have but little eflFect. Only where 
large quantities of nitrate fertilizers are applied to poorly 
aerated soils do they have great economic importance. 

156. Bacteria and the farmer. — Soil bacteria will go 
on doing their work in spite of anything the farmer does ; 
but he may, by proper methods, increase their usefulness 
to him. By the introduction of leguminous crops into 
his rotations, he is able to keep up the nitrogen supply, 
and by the plowing under of organic matter, he furnishes 
carbon for the formation of humus which assists in mak- 
ing available the various mineral plant-foods. By drain- 
ing wet lands, by adding limestone to soils that are acid, 
by the liberal use of barnyard manure, and by proper 
tillage methods, the farmer is able to get the greatest 
good out of these invisible, but powerful, workers in his 
behalf. 

SUPPLEMExNTARY READING 

Any textbook of bacteriology. 

Agricultural Bacteriology, H. W. Conn. 

Bacteria in Relation to Country Life, J. G. Lipman. 

Soils, Lyon, Fippin, and Buckman, pp. 421-474. 

Cyclopedia of American Agriculture, Vol. I, pp. 441-453. 

Agricultural Analysis, Vol. I (Soils), H. W. Wiley, pp. 519-572. 



CHAPTER XIV 
TILLAGE AND CROP ROTATIONS 

New reasons for cultivating soils and rotating crops 
are constantly being found ; but tillage and rotation 
were practiced long before any reason was known except 
that the yields of crops were increased by these prac- 
tices. Before any modern implements were made, the 
soil was stirred with bent sticks and rude devices of vari- 
ous kinds. These methods served the purpose of the 
time ; but as knowledge increased and better imple- 
ments were invented, the tillage of the soil was completely 
transformed. To-day, instead of being confined to a 
mere scratching of the land, it may include the intelligent 
use of a number of specialized implements during a sea- 
son. Although there are many reasons why cultivation 
of the soil is desirable, the following are probably the 
most important: (1) to improve the structure, or tilth 
of the soil, (2) to control the growth of weeds, (3) to cover 
manure, stubble, and other plant residues, and (4) to 
conserve soil moisture. Almost every tillage operation 
effects one or all of these. 

157. Improving soil structure. — Every plant requires 
for its best growth a looseness of soil that permits a free 
passage of air and an easy penetration of roots. When 
left undisturbed for a number of years, the soil becomes 
compact and is not in the best condition for crop growth. 
It is necessary, therefore, to loosen it by the use of some 
tillage implement. In cultivating the soil to improve 
L 145 



146 



The Principles of Agronomy 



tilth, attention must be given to the amount of moisture 
present. When a very wet soil is stirred, its particles 
are wedged together and the result is puddling, which is 
much more unfavorable to plants than is the merely com- 
pact condition of virgin land. 

Plowing should mean more than the mere turning over 
of the soil. If well done, every clod will be shattered 
and every particle have its relation to every other particle 




Fig. 41. — ^ Field in good condition for crops. 

changed through the shearing action which should take 
place when the plowed slice is turned over. As the soil 
falls into the furrow, it should be a granular, mellow mass 
of loose particles. The kind of implement that will best 
produce this condition varies with each soil. Sand or 
loam may be made mellow with almost any kind of plow, 
but a heavy clay without organic matter can be given a 
good tilth only when everything is favorable. Soil in 
good condition is shown in Figs. 41 to 43. 



Tillage and Crop Rotations 



147 



158. Controlling weeds. — Weeds are a menace to 
every farm. They thrive under all conditions that pro- 
duce crops, and it is impossible for ordinary crops to com- 
pete with them without the farmer's aid. Weeds are 
injurious, since they consume available plant-food and 
moisture needed by crops ; they shade and crowd out 




Fig. 42. — A good seed-bed. 



the more desirable plants ; and they often reduce the 
market value 6f crops. In arid regions where crop pro- 
duction is limited by lack of moisture, successful farm- 
ing cannot be practiced unless weeds are kept in check ; 
indeed, the quality of farming in any region may be judged 
by the thoroughness with which weeds are controlled. 
Some one has said that weeds are a good thing for the 



148 The Principles of Agronomy 

farm since they keep the farmer cultivating. Be this 
as it may, it is probable that a large part of the tillage 
operations are performed in order to kill weeds ; but the 
soil receives other benefits at the same time. IMuch 
energy is wasted in trying to control weeds which are 
allowed to grow and begin seed production before the 
cultivator is used. It takes a great deal of work to kill 
big weeds, and if their seeds have been scattered a new 
crop of trouble may be expected. The best time to kill 
weeds is just after they have germinated and before they 
have become well established in the soil. A mere stirring 
of the soil at this time is all that is necessary, but if they 
are allowed to get well established, a number of hoeings 
or cultivations are often required. 

The implement used to kill weeds depends on the crop 
grown, the kind of land, and the kind of weeds. On 
fallow land, an implement covering considerable area can 
be used to advantage. The spike-tooth, disk, and spring- 
tooth harrows, and implements with blades running just 
beneath the surface of the soil are effective. For tilled 
crops such as corn and potatoes, some sort of cultivator 
is used to advantage ; while in crops like alfalfa, the spring- 
tooth harrow is a good implement to eradicate weeds. The 
great secret of weed control with any tool lies in doing 
the work at the right time. 

159. Covering manure and plant residues. — Organic 
matter accumulates on the surface of any soil that is 
cropped. In the orchard, leaves fall to the ground ; in 
the grain field, stubble is left after harvest ; and in mead- 
ows that are to be followed by another crop, a sod must 
be disposed of. These plant residues cannot decompose 
readily if left at the surface. They need to be turned 
under and mixed with the soil in order to decay and give 
up their plant-foods as well as to assist in making available 



Tillage and Crop Rotations I-IQ 

the mineral matter of the soil. Farm manure is constantly 
being applied to the land, and must be covered and mixed 
with the soil if it is to do the most good. Practically all 
of this covering must be done with some kind of plow, 
although the disk harrow finds occasional use where the 
land has recently been plowed. 

160. Conserving moisture. — One of the most im- 
portant reasons for cultivating the soil is the conserva- 
tion of moisture. Even in regions of abundant rainfall, 
there are times when it is necessarv to save soil mois- 







h'lG. 43. — Orchard soil in goud tilth. 

ture ; and in arid regions, the very life of agriculture 
depends on conserving the scant supply of water (see Fig. 
44). 

If the soil is compact and hard, rain water will run oflp 
the surface rather than penetrate the soil where it can be 
used by plants. The soil must, therefore, be loosened in 
order that it may absorb moisture. The water that is 
in the soil moves by capillarity from particle to particle, 
and if the surface particles are pressed tightly together, 
the water will rise to the surface where it is lost by evapora- 
tion. This loss can be prevented by stirring the surface 
and forming a loose, dry mulch of earth which does not 



150 



The Principles of Agronomy 



allow moisture to escape readily. This mulch may be 
preserved by many implements, such as harrows and 
cultivators of various kinds. 

Rolling the land is often practiced to make the surface 
smooth and to break clods. Compacting the surface 
soil by the roller increases capillary movement toward 
the surface and therebv the loss of moisture. The fact 





M^^i 


.4^s 


iH 










•V, 





Fig. -44. — Cultivation while the crop is young greatly influences 
the yield. Delaware. 

that the soil seems more moist after a roller is used often 
misleads farmers who think they are actually saving water. 
161. Tillage of various crops. — The implements of 
tillage may be divided into three main classes — (1) 
plows, (2) cultivators, and (3) crushers and packers. 
The primary purpose of the plow is to loosen and pulver- 
ize the soil and make it more fit for the growth of plants. 
Plows are of numerous designs; no one kind is suitable 
for all conditions. The disk plow has given good results 
in many places, but the moldboard plow is doubtless 



Tillage and Crop Rotations 151 

suited to a much wider range. The old walking plow is 
rapidly giving way to some form of riding plow. 

Many different kinds of cultivators are used in pre- 
paring the seed-bed, in eradicating weeds, and in tilling 
crops during growth. Every farm should be equipped 
with several kinds of cultivating implements. A very 
useful and simple device used to smooth the land and to 
break clods without compacting the soil is made by at- 
taching a number of planks together with their edges 
overlapping. This planker, or float, is especially useful 
to precede the grain drill, since it scrapes off little eleva- 
tions and fills depressions, thus insuring a more uniform 
depth of planting. 

162. Reasons for rotation of crops. — Some sort of 
crop rotation has been practiced for many centuries. 
The reasons for this practice were probably not at first 
understood, even to-day all the effects of alternate crop- 
ping are not known ; but so many reasons are now known 
that there seems no good excuse for not practicing some 
kind of rotation on almost every farm. All crops do not 
require the various foods in exactly the same proportions ; 
some use more potash or nitrogen, while others need rela- 
tively more phosphorus or lime. If one crop is grown 
continuously on the same land, the available supply of 
certain elements is reduced and the yield will finally 
decrease ; but if crops with different requirements are 
alternated, the food supply of the soil is kept in a more 
balanced condition. Each kind of plant has a different 
rooting system and manner of growth. If shallow-rooted 
crops are grown continuously, only part of the soil is used, 
while an alternation of deep- and shallow-rooted crops 
overcomes this difficulty. 

One of the chief reasons for crop rotations is the im- 
provement of the soil. This is made possible by the use 



152 The Principles of Agronomy 

of legume crops, which fix nitrogen from the air (Fig. 45). 
The nitrogen fixed by these crops can be used by others 
which follow in the rotation, but it would be practically 
lost if the legumes were raised continuously. The control 
of plant diseases, insect pests, and weeds is made possible 
by the rotation of crops ; indeed, such considerations 
often cause the farmer to change his crops when he would 
not otherwise do so. Economy in the use of man-labor, 
horse-labor, machinery, and irrigation water results 




Fig. 45. — Every rotation should include a nitrogen-gathering crop. 

from the raising of a number of crops on a farm. These 
considerations alone, without any of the other benefits, 
would be sufficient reason for practicing rotations. 

163. Methods of crop rotation. — Careful planning is 
required in making a good rotation. The first essential 
is to decide on what crops can best be grown under the 
conditions. When this is done the quantity of each crop 
to raise and the placing of it can be determined. 

The following principles should be kept in mind in 



Tillage and Crop Rotations 153 

planning a rotation : (1) raise about the same acreage 
of each crop every year ; (2) have at least one cash crop ; 
(3) include a legume crop in the rotation ; (4) alternate 
tilled and non-tilled crops ; (5) alternate deep- and shal- 
low-rooted crops ; (6) alternate exhaustive and restora- 
tive crops ; (7) follow the best sequence of crops ; and 
(8) add manure to the right crops in the rotation. It is 
not always possible to conform to all of these principles, 
but they are useful guides. 

SUPPLEMENTARY READING 

Soils, S. W. Fletcher, pp. 46-188. 

Soils, Lyon, Fippin, and Buckman, pp. 663-6SL 

Cyclopedia of American Agriculture, \ ol. I, pp. 372-398. 

Physics of Agriculture, F. H. King, pp. 223-253. 

Crops and Methods for Soil Improvement, A. Agee, pp. 149-158. 

The Fertility of the Land, I. P. Roberts, pp. 61-107, 356-372. 

U. S. D. A. Farmers' Bulletins : 

No. 245. Renovation of Worn-out Soils. 

326. Building up a Run-doA\Ti Cotton Plantation. 

421. Control of Blowing Soils. 



CHAPTER XV 

SPECIAL SOIL PROBLEMS 

Every region has certain special soil problems not found 
in other places. Some of these are merely local ; others 
apply to a comparatively large area. On each farm, soil 
conditions are found that are not identical with those 
found on other farms of the same neighborhood. These 
special conditions make it necessary for each farmer to 
study his own soil in order to solve the problems which 
it presents. It is not possible to discuss, or even to under- 
stand, all the special soil problems. 

ALKALI 

In arid regions, there are millions of acres of land con- 
taining excessively high quantities of soluble salts which 
are usually spoken of as alkalies. The soil is rendered 
valueless by these salts if they are present in quantities 
that prohibit crop growth. Many soils, however, con- 
taining considerable alkali will raise good crops until 
strong concentrations of salt are brought near the surface 
by the evaporation of large quantities of water. In 
judging arid soils, it is necessary to know the amount of 
soluble salts present and their relation to the quantity 
causing injury to crops. In the management of such soils, 
the farmer should know how to prevent the accumula- 
tion of salts in the strata of the soil that is used ; and in 

154 



Special Soil Prohleins 



155 



regions where large quantities of alkali are already pres- 
ent, he should know how to reclaim the land. Effects of 
alkali on vegetation are shown in Figs. 46 and 47. 

164. Kinds of alkali. — Any soluble salt present in 
the soil in injurious quantities may be considered an 
alkali. The salts that most often cause injury are : sodiimi 
chloride, or common salt ; sodium sulfate, or Glauber's salt ; 
sodium carbonate, or sal-soda ; and magnesium sulfate, or 




Fig. 46. — Alkali spot with vegetation killed. 



epsom salt. In addition to these, sodium nitrate and a 
number of other salts do damage in some districts. 
Sodium chloride is injurious to vegetation when present 
in lower concentrations than any of the other salts men- 
tioned ; sodium carbonate, or black alkali, injures the 
soil when present in low concentrations by dissolving the 
organic matter and causing a hard crust to form. Plants 
will grow in the presence of relatively large quantities of 
the sulfates. 



156 



The Principles of Agronomy 



165. Efifect of alkali on plant growth. — The injury 
done to vegetation by alkali salts results largely from the 
shutting off of water from the plant on account of the soil 
solution having a greater concentration than the plant 
cells. By the law of osmosis water passes from the dilute 
to the more concentrated solution. In a normal soil, the 
root has a cell-sap with a higher concentration than the 
soil solution ; hence, water passes from the soil into the 




Fig. 47. — An orchard being killed by the rise of alkali. 



plant. When the soil solution is made too concentrated, 
on the other hand, water passes out of the roots into the 
soil and the plant dies. 

166. Reclamation of alkali lands. — The permanent 
reclamation of alkali lands rests on a removal of excessive 
salts by drainage. Other means may give temporary 
relief, but drainage is the only certain cure. In draining, 
the principles discussed in Chapter X are to be followed. 
Where the accumulation of alkali results from over- 
irrigating higher lands, the remedy is obviously the pre- 
vention of percolating water which carries soluble salts 



Special Soil Problems 157 

from above and concentrates them in the lower lands. 
Any practice which reduces evaporation, such as cultiva- 
tion, cropping, or the use of manure, tends to reduce the 
accumulation of these salts. 



ACIDITY 

Most crops require for their best growth an alkaline, 
or basic, reaction, although some grow better if the soil 
is slightly acid. Such important crops as the legumes can 
hardly be made to grow on an acid soil, since the bacteria 
which fix nitrogen in connection with growth on the roots 
of these crops require a basic reaction. Acid soils are 
most often found in humid regions where the basic ele- 
ments of the soil-minerals have been leached out, leaving 
the acid part behind, and in swamp lands where the decay 
of large quantities of vegetable matter results in the ac- 
cumulation of organic acids. The continuous applica- 
tion of ammoniun sulfa.te as a fertilizer to cultivated soils 
also finally results in an acid condition. 

167. Indicators of soil acidity. — An acid soil is indi- 
cated by the growth of a number of plants, among which 
are common sorrel, sour dock, horsetail, and corn spurry ; 
also by the failure of alfalfa and other legumes to do well. 
Blue litmus paper and a number of laboratory tests may 
be resorted to in determining acidity and the amount of 
lime necessary to correct the condition. 

168. Correction of soil acidity. — Acidity is best 
corrected by the use of some form of lime ; and acid soils 
usually pay handsomely for the expense of applying lime. 
Swamp lands high in organic matter often contain so much 
acid that it does not pay to correct the sour condition, 
especially since these soils usualh' contain an abundance 
of nitrogen. The kind of lime to use depends on condi- 



158 The Principles of Agronomy 

tions^ burned lime and ground limestone both accom- 
plish the result. Ground limestone, however, is usually 
cheaper and if fine enough, it is very effective. Ground 
limestone also has an additional advantage of destroying 
less organic matter than the burned, or caustic lime. 



EROSION 

One of the chief difficulties with which farmers of certain 
sections have to contend is the erosion of the soil, during 
w^hich fertility is washed out and at times the entire soil 
carried away. Some erosion goes on normally in all parts 
of the world ; indeed, it is by erosion that canons and 
ravines have been formed. It is much more intense, 
however, on land that is under cultivation. Many factors 
influence the amount of erosion that will take place. 
Among these are the quantity and season of rainfall, the 
slope of the land, the texture of the soil, the organic 
matter in the soil, and the crops riaised. 

Where the precipitation is light, erosion does not take 
place to any great extent unless the water falls in a 
few heavy storms and then only local damage is done. 
Erosion is more serious where the land has considerable 
slope and damaging streams are formed. A loose, 
coarse-textured soil is in more danger of erosion than a 
fine one that is compact. Organic matter in the soil 
reduces erosion by increasing its water-holding capacity 
and its absorptive power. 

169. Methods of preventing erosion. — Erosion cannot 
be avoided by the same methods under all conditions. One 
way of preventing it in hilly regions where the precipi- 
tation is excessive is to keep the land continually in crops. 
As soon as one crop is harvested something else is planted. 
This may later be plowed under as a green manure before 



Special Soil Problems 159 

the regular crop is seeded. Parts of the land most Ukely 
to wash are kept constantly planted to grass. 

Erosion usually begins by the formation of small 
furrows across the field. These rapidly increase until in 
time they become great washes. This condition may be 
avoided in the beginning by making regular channels with 
less slope to take care of all the run-off. The construction 
of terraces and plowing at right angles to the slope are 
useful devices for counteracting this tendency to wash. 
Large quantities of stable manure are also beneficial in 
reducing erosion. On some soils one or two of the 
methods given will successfully prevent washing, but in 
some sections every practice in soil management has to 
be directed toward reducing erosion. 



BLOWING 

In many sections, considerable difficulty is experienced 
with soils being blown away, leaving fields bare to the 
bottom of the plowed zone. After the land is plowed 
and a crop planted a wind-storm may carry the plowed 
soil and seed to a neighboring field. This condition, 
particularly serious in certain parts of the Great Plains, 
is also found to a lesser degree in many other regions 
having an arid or a semi-arid climate. In places where 
the soil drifts readily, farms have been abandoned over 
large areas. Houses, barns, and trees have been almost 
completely covered with soil and the entire surface of the 
land transformed by dust storms. 

In regions where the soil blows in this way, every opera- 
tion has to be directed toward holding the soil in place. 
The greatest care must be taken in plowing and harrow- 
ing. If the soil is left loose and fine, it is sure to be carried 
away. A fine, dry mulch such as is most effectual in 



160 The Princi'ples of Agronomy 

preventing evaporation of moisture cannot be used at 
all, but it is necessary to leave a surface of small clods 
which cannot be readily moved by wind. Plowing is 
usually done at right angles to the direction of wind. In 
this way the ridges break the force of the wind next to 
the ground, and the soil does not easily get into motion. 
170. Prevention of blowing. — It is on the long 
stretches of barren soil that the greatest injury is done. 
Where a large tract is left summer fallowed in dry-farming 
districts, blowing may begin and the whole district be 
affected. When the soil begins to move, it rapidly cuts 
the ground over which it passes. The great problem, 
therefore, is to prevent the first blowing. One effective 
means is the alternate cropping and fallowing of long 
strips of land. A crop, say corn, is planted in a long strip 
a few rods wide at right angles to the wind. Next to 
this comes a strip of fallow land, and then another of 
crop. In this way there is no large area of fallow land in 
one body and the soil does not start to blow. Seeding 
to grass or to some other permanent crop is sometimes 
necessary in places where drifting is worst. The methods 
to be used vary with conditions ; sometimes one measure 
will be sufficient, while at other times every known means 
must be used to prevent the soil's being carried away by 
the wind. 

METHODS OF JUDGING SOILS 

Since there are so many factors entering into the value 
of land, it is very difficult to tell just what it is worth. 
The amount of money involved in land transactions is so 
great that considerable care should be exercised to deter- 
mine as nearly as possible its true value. Often in one 
transaction there is sufficient money wasted to pay a 
man's expenses through an entire course at an agricul- 



Special Soil Problems 161 

tural college. The value of old land that has been farmed 
for a generation can be determined rather accurately ; 
but new land in a district where agriculture has not been 
practiced is more difficult to appraise. It is necessary 
on such lands to use every available means to aid in making 
a proper judgment. Among the things that must be 
taken into consideration are: (1) the native vegetation 
supported by the land ; (2) the topography ; (3) depth 
and structure of the soil ; (4) chemical analysis ; (5) 
crop yields obtained in the neighborhood ; and (6) 
external factors such as rainfall and nearness to market. 
The importance of rainfall is discussed in Chapter X, 
while Chapter XXXII considers market problems. 

171. Indicator value of native vegetation. — The veg- 
etation that grows naturally on a soil in its virgin state 
is one of the best indicators of its value. Certain plants 
show a condition of drouth ; others show an excess of 
moisture ; a number of species indicate an acid condition ; 
while others are a sure indication of the presence of large 
quantities of soluble salts. Since the entire flora of 
various sections is different, it is necessary to become 
acquainted with the plants of each region and determine 
what their growth indicates. When this is done the 
judging of virgin soils is greatly simplified. 

172. Topography of the land. — In many sections of 
the country, the topography of the land must be given 
considerable attention in judging its value. Where irri- 
gation water is to })e used, the land must be so situated 
that it can be reached by ditches. In regions where 
erosion does damage, the slope of the land is very impor- 
tant ; and in sections likely to be affected by frosts, the 
land should be so located that it has a good air drainage. 
The expense of tillage may be greatly increased if the 
surface of the land is rough, but the need of drainage is 



162 The Principles of Agronomy 

probably less on land of this kind than where the surface 
is flat. Under some conditions a rolling surface may be 
desirable, while under others smoother land may be pre- 
ferred. Under practically all conditions, however, the 
topography of the land must be given consideration in 
judging of its value. 

173. Depth and structure of the soil. — The depth of 
the soil and its general make-up are very important ele- 
ments entering into its value. A soil may be nearly 
perfect at the surface, but if it is only a few inches deep, 
it is of little value for some classes of farming. A shallow 
soil has a low water-holding capacity and its root-zone is 
not sufficient to give the best results for certain crops. 
The presence of a hardpan or of a streak of coarse gravel 
near the surface greatly reduces the value of any piece 
of land. Too often land is purchased on a surface ex- 
amination merely. This is a dangerous practice, since 
it is impossible by looking at the surface to tell what lies 
below. The condition of the sub-soil can best be studied 
by examining washes, railroad cuts, and wells, or by 
using a soil auger. It is impossible to make a sound 
judgment regarding land without knowing its nature to 
a depth of at least eight or ten feet. 

174. A chemical analysis of the soil tells the amount 
of plant-food contained, and gives some index to the best 
methods of handling the land. It shows which elements 
are likely to be deficient and which are abundant. It may 
also tell the reaction of the soil as well as the presence of 
excessive quantities of soluble salts. Special skill and 
considerable time are required to make a chemical anal- 
ysis ; hence, this item is often overlooked by practical 
farmers in judging land. If the chemical composition 
of a soil is not known, however, any judgment made of 
it must be somewhat superficial. 



Special Soil Problems 163 

175. The mechanical analysis of a soil shows its tex- 
ture, or the size of particles composing it. After a little 
experience the texture can be judged with fair accuracy 
without an analysis simply by feeling it. There is no 
difficulty, for example, in distinguishing between a 
coarse sand and a fine clay ; but in determining the tex- 
ture of an intermediate soil, a mechanical analysis is 
useful. Since the texture of a soil helps to determine 
what crops to grow, it should be known. 

176. Productivity. — The real value of land is deter- 
mined by what it will produce. Its chemical composi- 
tion and texture may seem favorable, but the,y count for 
little if crops do not thrive. For this reason it is not wise 
to judge hastily the value of land in a new project before 
crops are tried, even though chemical analyses and other 
indicators are available. So many factors enter into crop 
production that it is easy to overlook some of them, 
but all must be right if yields are to be satisfactory. 
Natural vegetation, topography, depth of soil, and 
chemical and mechanical composition are all good indica- 
tors of the value of land ; but the real " proof of the 
pudding is in the eating," and the best indicator of the 
value of land is its productivity. 



SUPPLEMENTARY READING v 

How to Choose a Farm, T. F. Hunt. 
Soils, E. W. Hilgard, pp. 313-370, 422-526. 
Soils, Lyon, Fippin, and Buckman, pp. 375-403, 718-740. 
The Soil, A. D. Hall, pp. 233-370, 289-297. 

Cyclopedia of American Agriculture, Vol. I, pp. 480-483, 513-531. 
Physics of Agriculture, F. H. King, pp. 92-107. 
Fertility of the Land, I. P. Roberts, pp. 303-341. 
Reports of Soil Surveys of U. S. D. A. Bureau of Soils and of State 
Experiment Stations. 



PART III 
FIELD CROPS 



CHAPTER XVI 
WHEA T ( Triticum satwum) 

The word " wheat " comes to us, Dondlinger ^ says, 
from the Middle Enghsh " whete," which in turn came 
from old English " liwaete." To this day the Germans 
call it " weizen." Strange though it may seem, both 
these words are related to others which mean white. 
Dondlinger further suggests that perhaps wheat was 
called white on account of rye and other grains being 
darker in color. 

Wheat is one of the oldest cultivated plants. Far 
back beyond the time when the first histories were written, 
this plant was nurtured. It seems to have been 
cultivated about thirty centuries before Christ, in 
China. It has also been found in the Lake dwellings of 
the Swiss, which discovery throws its history back into 
the prehistoric Stone Age. The Bible speaks of wheat 
harvest in very early times (Genesis xx. 14). With- 
out intermission this plant has served men down to the 
present day. 

Geographically, its origin is equally uncertain. The 
supposition that the Tigris-Euphrates valley is its birth- 
place is favored by de Candolle, Dondlinger, and Hunt. 
At any rate, when recorded history began, it was 
cultivated widely over the earth from China to Egypt. 
Perhaps the search for a center of spread suggested the 
Euphrates region. 

1 Book of Wheat, p. 1. 
167 



168 The Principles of Agronomy 

177. Relationships. — The Graminese is the botanical 
family to which wheat belongs. Many species of this 
family have become valuable for the production of seed 
which supplies food to both man and animal. These 
plants are designated as cereals, or grains. Into this 
category fall wheat, oats, barley, rye, rice, corn, the 
sorghums, and the millets. The Graminese include not 
only all of the cereals but also the common tame and wild 
grasses. The general field conditions for good wheat are 
well indicated in Figs. 48-53. 

178. Roots. — When wheat kernels germinate, they 
send out three roots which gather food from the soil to 
supplement that stored in the kernel. From these two 
sources, comes sufficient nourislunent to keep the young 
plant growing until it can establish itself. 

Once the green leaflets push into the sunlight, food 
manufacture begins. In the meantime roots grow out 
in all directions from a node, or joint, about an inch be- 
neath the surface, leaving the first ones to die because 
they are of no further use. These new roots grow out- 
ward from eight to twenty inches and then turn down- 
ward, rapidly reaching into deeper soil which is both a 
reservoir for water and a storehouse for plant-food. The 
depth to which they penetrate and the number of branches 
they send out depend on the looseness, the dampness, 
and the warmth of the soil ; on the time of the year ; 
and on the kind of wheat. The limits of variation are 
wide, yet under the most unfavorable conditions, the ex- 
tent of the root-system far exceeds what the ordinary 
person thinks it to be. 

One plant, showing roots seven feet two inches long 
profusely branched, was dug up at the Utah Experiment 
Farm at Nephi. The Minnesota Station reports finding 
a branch root every eighth of an inch for eighteen or 



Wheat 169 

twenty inches. Naturally many of these rebranch, 
thus forming a complete network in the soil. ]\Iore- 
over, many broken-off roots remained undisturbed. A 
total length of 2000 feet would probably be obtained 




Fig. 48. — A good stand of wheat. 



170 The Principles of Agronomy 

if all of these thread-like branches were placed end 
to end. 

179. The plant above ground. — Like all other members 
of the grass family, the wheat stem, known as a culm, has 
four or five distinct joints, or nodes, from two to ten inches 
apart in the mature plant. These nodes are solid, while 
the straw between, in most cases, is hollow and sometimes 
partly filled with pith. In the young plant, nodes are close 
together. Growth consists in a lengthening and thicken- 
ing of the internodes at a point just above the nodes. If 
the plants are so few that they do not fill the ground in 
which they are planted, underground nodes send out 
more culms, that is, the plant stools. 

Leaves grow upward from the nodes along the stem, 
clasping it closely half or two thirds of the way to the next 
joint. This part of the leaf is called the sheath ; that 
which springs away from the stem is called the blade. 
The leaves have parallel veins, a prominent one in the 
middle forming a midrib. Leaf blades may be large or 
small, smooth or rough ; some have edges so sharp as 
to cut the skin when brought in contact by a sliding 
movement. 

The head, or spike, consists of smaller sections borne 
alternately upon the rachis, a zig-zag stem, which may be 
studied in a picture or by carefully pulling off the spike- 
lets, as the sections are called. On each side of the 
spikelet is a coarse chaff, or glume. Between are two to 
five flowers so completely inclosed by other chaff, that 
pollen seldom escapes. This causes the flowers to be 
self-fertilized. Generally two of these flowers, but some- 
times only one or even three, bear a kernel, or berry. 

180. The kernel, dry and fairly smooth, has a deep 
groove running lengthwise, a number of fine hairs at one 
end, and a crumpled irregularity at the other. This 



Wheat 171 

wrinkling betrays the location of the embryo, or germ, 
which is not more than one fourteenth of the entire 
berry. The embryo is oily and can easily be removed 
with a pin or the point of a knife blade. The remainder 
of the berry is endosperm. Cut in two across the groove, 
the grain shows plainly under a hand lens three distinct 
layers; the bran outermost and the starchy part inside, 
with a layer of dark aleurone cells between. 

Wlien wheat is milled, flour comes from the white 
interior, the outer two layers making bran. In big 




Fig. 49. — A good yield of wheat, Pennsylvania. 

mills the germ is separated from the endosperm and made 
into flour, though this weakens the flour and also lessens 
its keeping qualities to a slight extent. 

181. Varieties. — Like all living things, wheat varies 
under different climatic and soil conditions. This is 
but natural, for included within the vast range of the crop 
are many distinct environments, to which nature and 
man attempt to fit plastic plant organisms, particularly 
if they are useful. East of the Mississippi, where the- 
winters are mild and the rainfall abundant, soft winter 
wheats are grown. Between this river and the Rockies, 



172 The Principles of Agronomy 

north of Nebraska, where the summers are dry and hot, 
and the wmters severe, having Httle snow, alternate 
freezing and thawing injure fall-planted grain ; hence, 
the farmers grow hard spring varieties. Because the 
winters are less rigorous and because snow protects the 
young plants from freezing, winter wheats do best on the 
Great Plains south of Dakota. The hot, dry ripening 
period favors hard grain. On the Pacific coast hard 
wheat tends to soften and amber wheat to whiten in re- 
sponse to mild winters and wet springs. Both the winter 
and the spring varieties are soft and starchy. The types 
of wheat in these districts neither begin nor end sharply, 
but blend into one another. 

All told there are upwards of 1000 so-called varieties. 
In 1895, the United States Department of Agriculture 
selected about 200 as being best fitted to various regions. 
As already indicated, no single choice could be made for 
the Great Plains alone. Clearly, then, no one variety 
is best for all localities. There are now existing eight 
distinct types. Once merely variations, their characteris- 
tics have become fairly fixed on account of continuous 
selection for one part of the earth. 

Certain definite qualities are, however, desired with 
reference to which varieties may be improved. Chief 
among these are : (1) high yield to the acre, (2) high weight 
for a bushel, (3) hardness accompanied by high nitrogen 
content, and (4) resistance to drouth, insects, or plant 
diseases. Better varieties may be secured by three 
methods : (1) by selection of the most desirable plants 
from ones now grown ; (2) by cross-breeding ; and (3) by 
the bringing of superior species from some other part of 
the world that has climate and soil reasonably like the 
one in question. Better cultural methods will also 
improve the health and consequently the yield of the crop. 



JVheaf 173 

182. Distribution and adaptation. — Although wheat is 
primarily adapted to growth in the temperate zone, it is 
by no means confined there. It has followed the Cauca- 
sian race into every continent and clime, and has also 
been cultivated by other races, for example, by the 
Chinese and other Asiatics. It is the bread-stuff of 
civilized man, having accompanied the spread of 
learning and implements. It was first cultivated, as we 
have seen, by the Egyptians ; all peoples have grown it 
except some in the Far East, where a similar grain, rice, 
supplants it. 

Wheat has matured from the equator to within two 
hundred miles of the Arctic circle at Dawson and on the 
Mackenzie River, both fully a thousand miles north of the 
United States. It is a common crop in Brazil, Peru, 
Egypt, India, Australia, United States, Russia, and 
Canada. Being best adapted to low plateau regions, it 
has spread round the world from east to west, wherever 
suitable conditions and opportunities have presented 
themselves. Nor is production closely limited by eleva- 
tion. In Russia and Palestine, regions fifty to one hun- 
dred feet below sea-level produce abundantly, while 
Ecuador and Peru show profitable crops at 10,000 feet, 
and in the Himalaya mountains wheat is produced at an 
elevation of 11,000 feet. About three-fourths of the 
crop, however, grows between 500 and 1500 feet above 
sea-level. 

At the equator the areas of production are high, with 
but little growing near sea-level. Near the extremes of 
height and latitude, no profit is made from the crop, 
production being entirely experimental. The elevation 
and latitude of the best regions indicate the desirability 
of moderate climates as regards both temperature and 
rainfall. With the perfection of dry -farming methods, 



174 



The Principles of Agronomy 



wheat has spread rapidly into drier districts until it is 
the principal crop on the dry-farm. It is only of late 
years that crops of higher acre returns have driven it 
from irrigated farms. 

Whether a crop yielding at best only a few dollars to 
the acre can be profitably grown on high-priced land is 




Fig. 50. — Wheat farms should be large to be most economical. 



questionable. The opinion of the best informed men 
seems to be that wheat should gradually pass to the 
less valuable areas everywhere, making room for the 
higher producing crops on land that bears high rent. 
About all it requires as to soil is fair fertility and tilth. 
It grows on sands, loams, .clays, and silts, avoiding the 
muck soils, which are too rich in organic matter. Deep, 
uniform loams, however, generally give the best yields 
where there is about twenty-five inches of rainfall. Good 
fields of wheat are shown in Figs. 48, 49, and 50. 

Hard and soft spring, hard and soft winter, and white 



Wheat 175 

wheats have adapted themselves to cHmatic conditions. 
These variations illustrate only a few of the attempts of 
the crop to suit more rigorous climates. Strains are 
continually becoming adapted to drier or to colder dis- 
tricts, where they were not successfully grown before. It 
is because of this widely increasing variation coupled with 
its manifold uses, that wheat has become such a general 
crop. 

183. Preparation of seed-bed. — The preparation of 
land for planting differs with the region. The chief 
difference is in amount of seed and time of sowing ; the 
methods of cultivation are primarily the same. 

In general, the methods include plowing in the autumn 
or late summer as soon after the crop is taken off as pos- 
sible ; leaving the land rough over winter so as to prevent 
run-off of rain or melting snow and to permit frost to break 
clods or sod into finer particles ; and harrowing in the 
early spring to prevent loss of moisture by evaporation 
and to keep down weeds. Fall-plowing ought to be as 
deep as the machinery and the horses or other power at 
the farmer's command will permit. Increased depth 
of plowing makes a better home for the plant and stores 
a greater quantity of moisture. In regions where spring 
planting is practiced, deep fall-plowing is still valuable, 
but in most cases the grain is not sown until it becomes 
warm the next spring. 

184. Seed and seeding. — Farmers had better use 
seed that is adapted to their system of farming. The 
stubble ought to be turned under as early as possible 
after harvest. Sometimes the land should lie through 
the winter without harrowing. If farmers disk it, and 
harrow after every rain that crusts the land or starts 
weeds, they have a loose, moist seed-bed free from weeds 
when planting time comes. 



176 



The Principles of Agronomy 




The grain ought to be 
screened to remove weed 
seed, rubbish, and 
shrunken kernels. Large, 
plump kernels give bet- 
ter yields than small or 
shrunken ones, because 
of the better start they 
give the young plants. 
But more than screening 
is necessary. For smut, 
the grain should be 
treated with formalde- 
hyde, one pint to fifty 
gallons of water, or with 
blue vitriol (copper sul- 
fate), one pound to five 
gallons of water. A good 
way is to dip a bag of 
wheat into a solution 
contained in a half barrel. 
About ten minutes is re- 
quired to wet all the 
grain. In the meantime, 
another sackful might be 
screened and filled to 
economize time. 

From three to six 
pecks of seed have given 
the best crops where no 
irrigation is practiced, 
while under irrigation 
four to eight pecks are 
used. For spring-plant- 



Wheat 



177 




178 



The Principles of Agronomy 



ing, earliness is essential. Fall-plowing makes possible 
earlier seeding, since disking is then all that is necessary 
before planting. During growth about all that can be 
done is to harrow. 

185. Harvesting. — There is no month in the year 
that is not a harvest season in some part of the earth. 
The season varies in the United States from May in 
Texas, to September in parts of the Northwest. Fall- 
planted grain ripens early and spring-planted grain late 
where the weather is cool or moist. 

Methods differ as widely as seasons. In many parts 
of the world, peasants still use the sickle or old-fashioned 




Fig. 53. — Thresher at work. 



cradle, but modern harvesters are rapidly winning in all 
progressive countries. In parts of western United States 
the binder has given way to the header, which removes 
the heads and elevates them into tight wagon-beds to be 
hauled off and stacked until ready for threshing. The 
header has been supplanted on some large farms by the 
combined-harvester, a machine that cuts, threshes, and 
sacks the grain in one operation. 



Wheat 179 

Binder-cut grain is shocked in the field where the straw 
dries sufficiently to permit easy separation of the grain 
from chaff. In some localities the wheat cut green is 
ripened by the translocation of starch from the straw, 
for which a long time in the shock is necessary. When 
threshing time approaches the farmer hauls and stacks 
the bundles, or he hauls directly to the thresher. When 
grain is stacked, the bundles are usually placed with heads 
in, so as to shed rain and resist the attack of fowls or 
rodents. 

186. Diseases. — Wheat is attacked by glume spot, 
wheat scab, rust, leaf blight, powdery mildew, and loose 
and closed smut. Of all these, however, rust and closed 
smut are most serious. 

187. Closed smut is a black, thread-like fungus which 
is spread by tiny, black spores that fly through the air 
and attach themselves to the wheat kernel. Sprouting 
about the same time as wheat, the long, slender tube of 
the smut enters the young plant and grows inside. It 
follows up the green, growing plant, dying in the lower 
part ©f the stem, as the straw hardens. At the time the 
heads form, the smut enters the kernel and grows inside. 
Infected kernels are like sound ones except they are dull 
in color, light in weight, and hollow. They break easily 
during threshing and when handled later, they scatter 
spores which cling to the sound kernels. On account of 
the resemblance in appearance to clean grain, the farmer 
may not notice this smut, though he finds when threshing 
a loss of from 10 to 40 per cent of the crop. This loss 
can be prevented by treatment described (Par. 184). Care 
should be taken that the formalin is 40 per cent for- 
maldehyde. After the grain is treated, it is hung up 
in bags or spread out on the barn floor to dry before 
planting. 



180 The Principles of Agronomy 

188. Loose smut enters the plant at flowerinr; time, and 
lives inside of the kerneh The disease is less prevalent 
than is that caused by closed smut. Treatment, however, 
is more difficult, since the spores are inside the kernels 
and cannot be reached by poisons. The only method is 
one known as the hot-water treatment, which is extremely 
hard to use successfully since, if the water be a few degrees 
too warm, the germination quality of the wheat is injured 
or destroyed. The grain is soaked for four hours in cold 
water, since heat more readily penetrates wet grain. 
To kill the smut, the wheat is immersed for ten minutes 
in water maintained at 133° F, The addition of the 
cold wheat makes constant heating necessary. Because 
of the difficulties, only small quantities of seed can be 
treated. This is then sowed on a seed plat which will 
yield clean seed for next season. 

189. Rust is a fungous disease which attacks the stem 
and leaf; that on the stem is the more serious. The 
spores live over winter in the standing straw or even in 
some other plant. In the spring, after germination, the 
fungi attack the wheat at any time. The injury consists 
in a failure of the grain to fill. Although considerable loss 
results, about all that can be done is to choose rust-re- 
sistant varieties, to rotate crops, to drain the land, and 
to avoid over-irrigation. 

190. Insects. — Hessian flies and chinch-bugs are the 
worst of the insect enemies of wheat. The chinch-bug 
attacks other crops, while the Hessian fly confines its work 
mostly to wheat. The latter is a fly which lays its eggs 
in the young plant. When the maggots hatch they rasp 
the young tissue and drink the sap. The chinch-bug is 
a beetle that eats the tender plants. They pass through 
no true larval stage, but hatch continuously throughout 
the early summer. Altogether these insects cause a loss 



Wheat 181 

of 10 per cent of the wheat crop. Spraying and catching 
in plow furrows are advocated, but perhaps clean farming 
and rotation are the better methods of control. 

In some districts, wheat suffers considerable loss from 
the wheat straw worm, which lays its eggs in the head and 
stem of the plant. The wheat joint worm works in the 
joints causing the grain to grow in bent positions, and 
therefore to be missed by the header. 

191. Weeds. — There are a few plants that have 
become such nuisances to wheat that they have gained 
reputations as pests. They steal plant-food and moisture, 
shade and crowd out the crop, hinder harvest, and lower 
the value of the grain by adding impurities. The weeds 
most common in wheat-fields of the Mountain states 
are the mustards, Russian thistle, sweet clover, and 
June grass (Bromus tectorum). Chess or cheat is com- 
mon in some parts of the East and middle West. 

The mustards cause considerable trouble in some dis- 
tricts. Since the seed lies for years in the ground, it 
accumulates strength under single-cropping. Rotation 
with intertilled crops is, therefore, an effective method of 
combating it. 

Russian thistle, a tumbleweed, and, for a long time, 
almost master of the Nebraska wheat farms, is now spread 
widely throughout the country. It scatters great num- 
bers of seeds by rolling them before the wind. Rail- 
roads introduce it into new localities ; irrigation water 
carries it to the fields ; sheep carry it in their wool ; and 
soon the whole region is sown. It is especially trouble- 
some on the dry-farm, but no matter where it exists it is 
a pest to be reckoned with. For protection, it is covered 
with sharp, spiny leaves. 

Sweet clover and June grass are easily controlled by 
thorough tillage, but they bother in haphazard farming, 



182 The Principles of Agronomy 

often increasing the labor and unpleasantness of harvest. 
Careful seed selection and proper tillage will lessen in- 
jury from chess. 

192. Quality in wheat consists of the ability its flour 
has to absorb large quantities of water thereby producing 
larger leaves. This is because of the presence of a nitrog- 
enous substance called gluten which, when wet, becomes 
sticky. Generally, the more gluten present and the 
more nearly it consists of 65 per cent gliadin and 35 per 
cent glutenin, the lighter is the bread made from a flour. 
Manifestly, however, stickiness cannot of itself cause 
bread to rise. Hard wheats produce angular flour particles 
rather than spherical or flat ones as does soft wheat. 
The edges permit the sticky gluten to take hold of the 
flour grains and to hold them more firmly together. 
When the yeast added to the dough " works," it produces 
carbon dioxide. Any substance in changing from a solid 
or a liquid to a gas expands. As carbon dioxide is liber- 
ated it needs more room ; hence, it pushes the dough 
aside, making it porous. Thus bread " rises," that is, the 
loaf increases in size but not in weight. The size and the 
lightness of the loaf depend largely on the quality of the 
wheat furnishing the flour. 

Considerable skill is required to pick out the best wheat 
from a number of samples. A clear, semi-transparent 
amber color and a horny, brittle interior indicate high 
percentage of protein. High nitrogen content gives any 
cereal a greater food value, and it gives wheat flour more 
desirable bread-making qualities. Shrunken kernels con- 
tain much protein, but the gluten is poor. Maturity, 
then, is also an essential characteristic of best quality 
in wheat. High nitrogen and low moisture content in 
a soil tends to produce wheat that is rich in nitrogen. 

Millers and bakers know that some varieties of wheat 



Wheat . 183 

are much more valuable than others for flour-making. 
Hard varieties often bring increased prices on the market. 
The most important factor in determining quality in 
wheat is climate. Regions having cold winters followed 
by hot, dry summers which cause wheat to ripen rapidly 
grow hard grain. Excessive rainfall as well as mildness 
causes wheat to soften, thereby lowering its gluten con- 
tent. Starchy grain taken to a hard-wheat district 
hardens in a few years, just as hard ones moved to soft 
districts gradually lose their horny texture. Accom- 
panying changes in chemical composition likewise result. 

193. Uses and value. — The principal use of wheat is 
for human consumption in the form of bread. Flour, 
carefully graded in the large mills, is handled by whole- 
sale dealers who distribute it to homes or bakeries. Bread 
is the chief diet of all highly civilized nations. 

Besides being used for bread-making, flour is made 
into pies, cakes, crackers, doughnuts, pancakes, and a 
number of other common foods. In addition, many cereal 
breakfast foods are made from wheat. Formerly, only 
flour was saved at the mill. A waste-spout carried the 
bran, shorts, and other by-products into the stream that 
turned the water-wheel. Now these comprise a valuable 
part of the output. Bran and shorts are among the most 
valuable of stock-feeds. Even the dust brushed from the 
wheat kernels before grinding is collected and mixed with 
the bran. 

Cracked, or broken wheat is better, especially for 
swine, than whole wheat, which in some cases escapes 
mastication and does not digest. The price of wheat, 
however, generally compels the use of cheaper grains, 
such as corn and barley. The dependence on wheat 
for such a variety of food products gives it a value 
higher than dollars and cents. Nearly twice as much 



184 T\e Principles of Agronomy 

wheat is ground for dietetic purposes, as of all other 
grains combined. 

In cash value as well as in total yield, it is second to 
rice which alone feeds over half of the inhabitants of the 
earth. In the United States corn is the largest crop, with 
wheat second. For the world, however, corn, oats, and 
wheat each produce about four billion bushels, while 
rice totals five billion. 

Potatoes, other root crops, and fruits all feed a greater 
number of persons for a given area than wheat, but main- 
tain them at a lower standard of living. Wherever the 
standard of living is increasing, as it is in Germany, 
Russia, and parts of India, the use of wheat is spreading. 

Dondlinger ^ says : " The great intrinsic food value of 
wheat ; its ease of cultivation and preparation for use ; 
its wide adaptation to different climates and soils; its 
quick and bountiful return ; and the fact of its being 
paniferous and yielding such a vast number and variety 
of products are all factors that enhance the value of the 
wdieat grain. Its combined qualitative and quantitative 
importance gives to wheat a great superiority over any 
other cereal, and causes it to be dealt in more extensively 
upon the speculative markets than any other agricultural 
product. As an essential part of the food of civilized 
man it assumes an importance so vital as to be domi- 
nating." 

194. Storage. — The easiest way to store wheat, or 
any other grain for that matter, is to put it in sacks as 
it comes from the thresher, and to pile them on the 
ground. The owner uses this method as a makeshift 
until he can do something else with the grain : either sell 
it or store it permanently in a place where it will be pro- 
tected from the weather. Sometimes the sacks are left 
1 Book of Wheat, p. 8. 



Wheat 



185 



exposed ; sometimes they are covered with pieces of 
canvas having weights tied to the corners to hold them 
down. 

As such storage permits considerable damage in wet 
storms, the farmer generally uses it only for that part of 
the crop that he intends to sell. Whatever he keeps over 
winter, he puts in bins in granaries. Since frost does not 
injure wheat, the granaries are exposed as much as pos- 
sible to cold, thereby reducing to a minimum damage 
from mice and vermin, which cannot stand extreme cold. 







H».X &otd Con Wkc:a+, f.o'n D.^ «o.fTi. Paia.Ab»r« CecKe Cft. H«rv«a*ed v. ith Csmb'.nttri H»rva»4a». 




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Fig. 54. — Gain in weight of wheat after harvest in arid regions, Utah. 



To further ward off attacks of these destructive pests, 
some farmers set their granaries on posts three or four 
feet above ground. On top of the posts, before the joists 
are laid, they place inverted tin pans, which prevent mice, 
rats, and squirrels from climbing up the posts. Tight 
doors also deny them admittance. 

The grain that is sold has very different treatment. 
The part that goes to the Pacific Coast is left in sacks, 
either being piled up on the wharves in heaps several 



186 The Principles of Agronomy 

blocks long by a hundred feet high, where it waits ship- 
ment, or else being stored in warehouses, some of which 
cover several acres. Still another part of our local export 
stops in the neighboring towns to be ground into flour. 
These mills have large bins holding from one thousand 
to fifty thousand bushels, storehouses which are really 
miniature elevators. 

195. Elevators. — Particularly in the region of the 
Great Lakes, elevators are becoming more common. 
Here sacks are not used, and men handle the loose grain 
almost entirely by machinery. It pours directly from 
the thresher into dump wagons. The loose grain 
finds its way into cars which carry it to the elevator 
platforms. Trap-doors open chutes, down which it pours 
into vast cellars. Endless carriers elevate the grain and 
distribute it to bins from which it runs like water down 
chutes into cars, boats, or mills. Not once is it moved 
by hand. Terminal elevators are immense affairs, occa- 
sionally holding three million bushels of grain. Scattered 
far and wide over the country are smaller structures 
sometimes tributary to the large concerns and some- 
times independent. One of the great elevators used in 
the handling of the grain crop is shown in Fig. 55. 

Any grain containing excessive moisture molds and 
ferments in storage thus losing much of its value. For- 
merly, a considerable amount of grain was lost in this way 
in the close holds of ships that carried it from the United 
States to Europe. Grain must be well-dried before being 
stored anywhere. In arid regions, it is so dry at harvest 
time that it can be stored at once without danger. Indeed, 
it gains in weight by the absorption of moisture, elimi- 
nating shrinkage. Wheat shipped from California gains 
enough in weight before it reaches London to pay the 
cost of hauling. 



Wheat 



187 



Wheat is often bought and stored to await a rise in 
price. Small storage charges are made for rented space 
in elevators, about two cents a bushel for the first thirty- 
days and a half cent for each additional thirty days. 
Sometimes farmers store grain independently; occasion- 
ally a number cooperate and run an elevator. By far 
the greatest number sell at threshing time. Much 




Fig. 55. — Large terminal elevators help to handle the world's grain crop. 

grain, however, is contracted in the spring before it is even 
planted. 

196. Marketing. — It is difficult for the ordinary 
farmer to know whether to sell at harvest or during the 
following winter. Often he needs the money and must 
dispose of part or all of the grain at once. To sell the 
entire crop at the same time saves him labor and storage 
expenses, but he loses any advantage from subsequent rise 



188 The Principles of Agronomy 

in price. This rise sometimes does not pay the expense ; 
indeed, there may be a drop instead of a rise. The intel- 
ligent farmer studies the markets. " Will it pay to 
store? " is the question he must answer in consideration 
of the time to sell. 

Local merchants and mills buy from growers and sell 
to shippers. Large companies also keep agents in the 
field who contract for grain with the individual farmers. 
In well-developed districts most of the grain is handled 
in this way. A few cooperative farmers' companies ship 
their own products. When successful, these net large 
returns, but the undertaking is attended with much risk 
as a business venture. 

A great avenue for advance in marketing is a more 
systematic grading. In the grain trade of Chicago wheat 
is graded as follows : 

White Winter Wheat, Nos. 1, 2, 3, and 4. 
Long Red Winter Wheat, Nos. 1 and 2. 
Red Winter Wheat, Nos. 1, 2, 3, and 4. 
Hard Winter Wheat, Nos. 1, 2, 3, and 4. 
Colorado Wheat, Nos. 1, 2, and 3. 
Northern Spring Wheat, Nos. 1 and 2. 
Spring Wheat, Nos. 1, 2, 3, and 4. 
White Spring Wheat, Nos. 1, 2, 3, and 4. 

The grades are based on soundness, cleanliness, weight, 
color, and uniformity. No. 1 being best. Poor wheat is 
called " no grade." These grades have become so nearly 
standard that a buyer accepts a certificate from the in- 
spector without looking at the grain or seeing a sample 
of it. 

197. Prices vary a few cents according to grade. In 
some sections, little reliable grading is done. The grain 
buyer, making a shrewd estimate of the grade, knows 



Wheat 189 

what he can get for it, while the farmer selHng simply 
" wheat," must take the price of grade No. 3, though his 
grain may be No. 2 or even No. 1. Generally, the agent 
will pay less than he should. Therefore, a standardiza- 
tion of wheat and other grain would save money for 
growers. 

To assist in handling the grain, enormous exchanges 
are maintained at Chicago and smaller ones in other 
cities. The Exchange is a large room in which buyers 
and sellers meet to transact business. Much of the 
time, confusion prevents ordinary conversation, hence a 
finger sign-language is used. Only large quantities of 
wheat (about 5000 bushels) are considered. Speculators, 
who have entered these exchanges, buy simply to sell for 
gain — not to assist in the legitimate grain handling. They 
buy up certificates and hold them, expecting prices to 
go up. 

If a man buys a million bushels and holds it for a time, 
he is making a " bull " speculation. On the other hand, 
owning no grain at all, he may sell wheat at a given price, 
agreeing to deliver at a future date. He expects the price 
to fall when he can purchase wheat to fill his contract at 
a lower price than he receives from his customer. Such 
sales are known as " futures." When a man plunges in 
this way he is a " bear " speculator. 

SUPPLEMENTARY READING 

The Book of Wheat, P. T. Dondlinger. 

Wheat Growing in Canada, the United States, and Argentina, W. P. 

Rutter. • 

Story of a Grain of Wheat, W. C. Edgar. 
Cereals in America, T. F. Hunt, pp. 26-136. 
Field Crops, Wilson and Warburton, pp. 135-174. 
Field Crop Production, G. Livingston, pp. 99-144. 



190 The Principles of Agronomy 

Wheat Fields and Markets of the World, RoUin E. Smith. 

Story of a Loaf of Bread, T. B. Wood. 

Wheat and Flour Investigations, Harry Snyder, Minnesota Bui. 

No. 85. 
Cyclopedia of American Agriculture, Vol. II, pp. 660-670. 
Wheat, M. W. Ten Eyck. 

Principles of Irrigation Practice, J. A. Widtsoe, pp. 240-253. 
Southern Field Crops, J. F. Duggar, pp. 32-67. ^ 
U. S. D. A. Farmers' Bulletins : 

No. 132. Insect Enemies of Growing Wheat. 

219. Lessons from the Grain Rust Epidemic of 1904. 

250. The Prevention of Wheat Smut and Loose Smut of 

Oats. 
267. Buckwheat. 

507. The Smuts of Wheat, Oats, Barley, and Corn. 
534. Durum Wheat. 
596. The Culture of Winter Wheat in the Eastern Half of 

the United States. 
616. Winter Wheat Varieties for the Eastern United States. 



CHAPTER XVII 

CORN OR MAIZE {Zea Mays) 

Because " corn " was a common term in Europe for 
all grains, " Indian corn " was the name applied to field 
corn, or maize. Early European visitors found the natives 
growing it in Peru, Mexico, and New Mexico. Indians 
taught the English settlers at Phmouth how to grow the 
crop, fertilizing each hill with a fish. Captain John 
Smith of the Jamestown settlement saved the settlers 
from starvation by forcing the Indian Chief Powhatan 
to sell him corn. It must have seemed strange to these 
pioneers to find in America a plant of such vast impor- 
tance to them. Some of the American field conditions of 
corn culture are shown in Figs. 56 and 57. 

198. Relationships. — Maize belongs to the grass 
family, but is not closely related to the common grasses 
or to the other cereals. So far as we know, it has no 
close relatives in existence to-day. 

199. Roots. — The first roots sent out by a young corn 
plant to start growth remain, but the larger part of the 
root-system, like that of wheat, develops from a node about 
an inch below the surface of the ground. As corn is 
generally grown in hills, the fibrous roots, in order to 
occupy all the soil, grow outward for eighteen or twenty 
inches and then turn downward. Other roots reach down- 
ward at once, thus leaving little unused soil. While the 
plant is young the roots grow rapidly, never, however, 

191 



192 



The Principles of Agronomy 




Fig. 56. — Good corn culture. 




Fig. 57. — Corn on an irrigated farm, Utah. 



Corn or Maize 193 

reaching quite so large a development in proportion to 
the size of the entire plant as those of wheat. To anchor 
itself more firmly the plant sends out from the first one 
or two nodes above ground another whorl of roots. 
These enter the soil at an angle, bracing the stalk 
much as guy-ropes do a tall pole or derrick. Because 
these roots do little food gathering, but simply aid the 
plant in resisting wund, they are known as brace roots. 

200. The cuhns, or stems, of maize resemble wheat 
culms in having nodes and internodes, but differ from 
them in having a stem filled with soft pith through which 
fibers are scattered. This pith is inclosed in a case of 
hard, compact fiber that serves as support. Each inter- 
node, except the top one, has a narrow groove on the 
side that bears the leaf. The length and diameter of the 
internodes vary so greatly as to cause the size of the plant 
to range from eighteen inches to thirty feet in height and 
from a half inch to a number of inches in thickness. The 
common range is from four to twelve feet in height and 
from one to two inches in diameter near the ground. One 
stalk grows from each kernel, sometimes sending out from 
a lower node branch stalks called suckers. 

201. The leaves, growing from the nodes on alternate 
sides, clasp the stem part way to the next joint, and then 
send out a blade just as do the leaves of wheat. They 
are parallel-veined, with a distinct midrib, edges that cut, 
and a rough, hairy surface. As the outer part of the leaf 
grows faster than the inner, wrinkling is produced. The 
edges are thinner than the middle causing the leaf to roll 
when it wilts. Because the plant grows rapidly about 
tasseling season, a large leaf area is necessary to take in 
carbon dioxide for the manufacture of food. In a good 
stand, the total leaf area, when greatest, is about six times 
that of the land on which it is grown ; hence enormous 

o 



194 The Principles of Agronbmy 

quantities of water are transpired to maintain growth. 
Wilting often takes place, but the rolling of the leaves 
reduces loss of water and turgidity is restored automati- 
cally. 

202. The flower. — Each ear develops in the axil of 
a leaf from a bud in the groove, part way up the plant. 
Kernels develop from the ovary part of the flower on the 
cob. Each is fertilized by pollen borne on the tassels. 
This alights on the exposed end of the silk which connects 
with the ovary. 

The wind blows the pollen about so freely that much 
is lost. To insure itself against this loss each plant pro- 
duces from 9000 to 45,000 pollen grains for each silk, 
or about 2000 ovules and from eighteen to seventy mil- 
lion grains of pollen. Many of the silks are fertilized 
by pollen from another plant. In fact, the plant seems 
to invite cross-fertilization by ripening and letting its 
pollen go before the silk of the same plant is ready to 
receive it. 

203. The ear. — Since the cob is several united spike- 
lets, each of which bears two rows of kernels, the number 
of rows is even. An ear having an odd number is a great 
curiosity. Often an ear has more rows at the butt than 
at the tip, but these rows drop out two at a time. Because 
the tip of the ear fills last, this part of the cob is frequently 
bare and the kernels are nearly always smaller and more 
nearly round here than in the middle of the ear. At the 
butt they are larger but irregularly shaped. Fig. 58 
shows good and uniform ears of corn. 

All kernels are covered with a membranous hull that 
loosens when the grain is soaked in warm water. The 
embryo is near the cob on the side toward the tip of the 
ear. The remaining part, about seven-eighths of the 
whole, is endosperm — corneous if hard, starchy if white. 



Corn or Maize 



195 



The corneous endosperm contains more nitrogen than the 
white and is more valuable for feed. 

Abnormalities of structure occasionally manifest them- 
selves as grain on the tassel, as divided cobs, as one ear 
borne at the tip of another, and as tassels borne on or 
between cobs. 

204. Types. — The corn that Europeans first found the 
Indians growing in America was much inferior to the 
better kinds now used. Although there is but one species, 




Fici. 5S. — Good ears of dent corn. 



this varies so widely that little difficulty is experienced in 
changing a variety or in improving it. It is only about 
sixty years since corn improvement was begun ; yet within 
this short period has come most of the advance made 
since white people first grew the crop. Widely different 
uses of corn and varying conditions of growth have given 
rise to six very distinct groups of varieties better known 
as types. These are: (1) dent, (2) flint, (3) sweet, (4) 
pop, (5) soft, and (6) pod. 

205. Dent com is by far the most important, as it in- 
cluded over four-fifths of the total corn crop. It is so called 
because the corneous endosperm, which partially incloses 
the soft, starchy endosperm at the crown without cover- 



196 The Principles of Agronomy 

ing it, allows the kernel to shrink or dent in ripening. 
The dent may be very shallow or so deep as to give con- 
siderable roughness to the ear. The kernels are not too 
hard for animals to chew. 

Desirable ears are six to eight inches in circumference 
and eight to ten inches in length, with deep, wedge-shaped 
kernels extending well over both tip and butt. Cylindri- 
cal ears with small butts and no bare cob at the tip are 
most desirable, because the shelling percentage is high. 

206. Flint com is so called on account of the hard, 
glossy kernels, the crowns of which are roimd and smooth. 
The dent fails to develop because hard endosperm covers 
the crown as well as the sides of the kernel, entirely inclos- 
ing the starchy part. The kernels are more nearly round, 
wider, and more shallow than dent kernels. Less corn 
in proportion to cob grows on the flint ear. Flint corn 
differs from dent in having a longer, slimmer ear, a larger 
shank which increases the difficulty of husking, and 
fewer rows of kernels. 

Dent varieties usually require a longer time to mature 
than flint, but this is not always the case. Although 
next to dent in importance, flint corn produces somewhat 
less than one-twelfth of the total crop. 

207. Sweet com has sugar instead of starch in the 
endosperm. The glucose sugar shrinks evenly while 
ripening, giving the kernels a distinctly wrinkled appear- 
ance. In shape, the ears resemble dent. Its ripening 
period is medium. Sweet corn does not represent more 
than 2 or 3 per cent of the total crop, most of this being 
used in the canning industry, and for table use. 

208. Pop com is either smooth like flint or sharp on 
the top of the kernels, which are so very hard that animals 
cannot chew them easily. This, the dwarfishness of the 
plant, and the small size of the ears, which are generally 



Corn or Maize 197 

an inch thick and four to six inches long, prevent its 
being used as stock-feed. Pop corn yields less than 1 
per cent of the corn produced in this country. It is 
largely consumed as " popped corn." Popping consists 
of a rapid heating which causes the kernel to explode and 
turn inside out. The plant suckers freely, bears several 
ears, and matures early. 

209. Soft or flour com resembles white flint in appear- 
ance both as to ear and plant, but has no hard endosperm 
at all. Because it is readily ground, it was grown by the 
Incas of Peru for food. 

210. Pod com received this name because each kernel 
is inclosed in a husk. The ears are short and the plants 
smaller than flint. It is used to some extent for cattle 
feeding, but neither this nor soft maize are grown on a 
commercial scale. 

211. Varieties. — There are nearly three hundred 
varieties of corn, but as already mentioned, these may 
be changed and improved so easily that, in many cases, 
the same variety has several sub-varieties called strains. 
Many varieties are known by different names in different 
localities, causing a hopeless tangle out of which little 
can be cleared. Improved Leaming, Reid's Yellow 
Dent, Boone County White, Silver King, Silver Mine, 
Gold Mine, King Philip, Longfellow, Legal Tender, 
Wisconsin No. 7, and Minnesota No. L3 are wide-spread, 
standard varieties. 

212. Distribution. — The total production of corn 
from 1905 to 1909 was 3,585,418,600 bushels yearly. 
Austria-Hungary, Argentina, Russia, Egypt, Australia, 
and Mexico in the order named produced corn, though 
the LTnited States grew 76 per cent of the whole, producing 
about two-thirds of its crop, or one-half the total output 
of the world, in eight states : namely, (1) Illinois, (2) 



198 The Principles of Agronomy 

Iowa, (3) Missouri, (4) Nebraska, (5) Indiana, (6) Kan- 
sas, (7) Ohio, and (8) Texas. These eight states have an 
area in square miles equal to 22 per cent of the area of 
the United States, and to one-third of 1 per cent of the 
total land area of the world. One-half of all the corn on 
earth would not be produced on one three-hundredth 
part of the earth's area if this particular section were not 
especially adapted to corn production. 

213. Factors in production, — The four important 
factors that determine the successful production of corn 
are: (1) market conditions, (2) length of growing-season, 
(3) rainfall, and (4) soil. 

If the crop, its manufactured products, or the meat 
produced by feeding it, did not sell to advantage, the crop 
could not be grown though the climate and soil were 
ever so favorable to its production. The corn belt of 
the Ignited States has shipping facilities through a net- 
work of railroads and waterways ; Chicago and St. Louis, 
the great meat markets of the world, are at hand ; vast 
factories in which starch, glucose, oil, and sirup are made 
have grown up in the region. It is hard to conceive of 
more favorable marketing conditions than here exist. 

214. Adaptation. — Corn is extremely sensitive to 
frost — so much so that the length of its growing-season 
is measured b\' the last spring frost and the first one of 
autumn. One slight frost in the fall injures the plant to 
such an extent that, although a month of warm weather 
follows the freeze, this first drop of the thermometer, 
even though of only a few hours' duration, ends its grow- 
ing-season. An even temperature free from cold nights is 
desirable, but absence of frost for nearly five months is 
absolutely essential. In the corn belt there are no late 
spring frosts and no early fall frosts. 

The water requirement in proportion to dry matter 



Corn or Maize 19§ 

produced is less for corn than for other grains. This 
does not indicate, however, that corn needs less water 
than the small-grains. It grows very rapidly after tassel- 
ing begins. In one case it was found that 1300 pounds 
of dry matter to the acre was produced in a single week. 
Thus great quantities of moisture are needed in the grow- 
ing-season. Experience has shown that the yield of 
corn is almost directly proportional to the moisture supply 
during a few critical weeks. 

Corn responds very readily to the presence of organic 
matter in the soil. Soils that are loose, black, and rich 
in organic matter are common in the corn belt. The crop 
is grown on the heavier soils, but is at its best on the 
loessial soils, which are easily kept loose and friable. 
The physical condition of the soil is important, since good 
tilth allows soil moisture to move freely to the roots. 

The average acre-yield for the United States from 1900 
to 1910 was 24 bushels; for Connecticut, 39.9 bushels; 
Massachusetts, 38.3 bushels ; Maine, 37.3 bushels ; Ohio, 
36.9 bushels; and Pennsylvania, 36.8 bushels. In the 
South, the yields were less, but the methods of culture 
were also infinitely poorer. Systematic handling of the 
crop, it is estimated, should in the North give a 100-bushel 
crop and in the South even more. The bumper crop of 
226 bushels grown by a Tennessee boy is worthy of 
attention. 

215. Preparation of the seed-bed. — Deep fall-plow- 
ing seems rather advantageous to corn because it enables 
winter moisture to sink into the soil, and allows frost 
to mellow the seed-bed. Since large quantities of organic 
matter cause abundant growth in corn, moderate appli- 
cations of farm manure usually pay. Corn is a good crop 
to follow clover, alfalfa, or other sod-producers. Whether 
plowing is done in spring or fall, the plow should cover 



200 The Principles of Agronomy 

all the vegetable material to insure decay. In the spring 
the disk or spike-tooth harrow should fine the seed-bed 
until a loose, friable surface is ready to receive the seed. 

216. Seed and planting. — After the farmer has decided 
upon the variety he wishes to grow, he should choose 
seed adapted to the climate. Seed should be selected 
in the field before the grain is cut in order to identify 
high-producing, early-maturing plants. 

Because both frost and moisture injure the germinating 
power of corn, seed requires a warm, dry, well-ventilated 
place for storage. A good way is to hang the ears in 
strings, in such a way that they do not touch. Kernels 
from butt, tip, and middle of ear have equal value, al- 
though irregular butt and tip kernels may interfere with 
even distribution by planters. In most cases, no treat- 
ment before planting is needed. 

On some large farms, machines do the planting, but 
on most small farms, seeding is done with hand planters. 
Although there seems to be no advantage in planting 
deeper than one or two inches in humid sections, farmers 
of the West consider three to six inches none too deep 
because they find it necessary to plant below the dry 
surface soil. In heavy soils, planting should not be so 
deep as in light, sandy ones. 

Thickness of planting varies from more than a kernel for 
each square foot to one for each fifteen or twenty square feet. 
Medium thick planting, a kernel for each three or four 
square feet, usually gives the most grain. Seed is nearly 
always planted in rows and generally in hills. A common 
practice is to plant three or four kernels in hills two to 
five feet apart, with three to five feet between rows. 
About a peck of shelled corn sows an acre for grain produc- 
tion, but, for fodder or silage, thicker planting is desir- 
able. 



Corn or Maize 



201 



The time for planting is usually later than for the small- 
grains. Sometime in May is usual, though the late days 
of April and the early ones of June are suitable in some 
districts. No date can be set, for the frost and moisture 
conditions vary with the locality. 

217. Treatment of the growing crop. — Before corn 
comes up, a harrow run over the field will break the crust 




Fig. 59. — Effect of irrigation on yield of corn, Utah. 



and kill weeds that have just germinated. After the 
hills can be seen plainly, the harrow may be used until 
the plants are so large that they would be injured by the 
implement. The cultivator may be used as soon as the 
rows show well and it should follow at intervals of two 
weeks, or thereabouts, except that, after every heavy 
storm or irrigation, cultivation can be given to advantage 



202 



The Principles of Agronomy 



as soon as the land will permit. Some hand-hoeing may 
be needed to keep down weeds in the rows. Shallow is 
better than very deep cultivation, and frequent better 
than occasional. 

It is usually unnecessary to irrigate corn until it has 
a good start, but in case the soil is too dry to germinate 
the seed, it is advisable to apply the water before planting 



INCREASE IN YIELD OFGRAIN AND STOVER PRODUCED BY -40 ACRE. 
INCHES OF IRRIGATION WATER APPLIED TO DIFTERENT AREAS. 



%■* 









5 4 



Fig. 60. — Results of irrigation on corn. 



rather than after. The time for irrigation will be indi- 
cated by a dark color and by the wilting of the leaves. 
The amount and distribution of irrigation water will 
vary greatly with conditions, but it is rarely necessary 
to use more than thirty inches during a season. It is 
usually more convenient to apply water by the furrow 
method. The charts (Figs. 59 and 60) show the results 
to be secured from judicious irrigation. 



Corn or Maize 203 

218. Harvesting. — A good time to begin to harvest 
corn is when the grain is just hard enough to resist pres- 
sure from the thumb nail. About this time the husk 
turns whitish, but the fodder remains green if frost has 
not nipped the leaves. Nothing is gained by allowing 
maize to go unharvested after it is ready, and since, in 
many sections, frosts are likely to do considerable injury 
to the fodder, much risk accompanies late harvesting. 

Some growers turn hogs and occasionally cattle into 
the corn to harvest it on foot. Rape or cowpeas sowed 
between the rows add much to its pasture value. The 
practice of " hogging-off " is increasing. Sometimes the 
ears are pulled by hand or machinery and the stover 
pastured. Again the leaves may be stripped oft" and 
saved, or the top of the stalks and leaves cut. Most 
satisfactory, perhaps, is the method of cutting off the 
stalks at the ground and stacking them in shocks in the 
field or in the yard to be husked later. 

There are several kinds of corn-cutters, some of which 
bind and shock the corn. Much maize is cut with long 
knives and short-handled hoes. Husking is commonly 
done by hand, in spite of the fact that there are machine 
buskers and shredders. The great expense and the 
complicated, easily-injured mechanisms have retarded 
the universal adoption of c(?rn-harvesting machinery. 

219. Silage. — Corn to be made into silage is allowed 
to stand in the field until the grain is in the roasting-ear 
stage, when it is cut, usually with a binder, and hauled on 
a low wagon to the silo. Here it is cut into pieces a half 
inch long, or thereabouts, and blown into the silo. It 
settles into an air-tight mass and preserves itself for 
green feed in winter when dairy stock have no pas- 
ture, or in the hot, dry summer when succulent feed is 
scarce. 



204 The Principles of Agronomy 

220, Enemies. — Weeds cause the most difficulty 
in corn-growing, but as already pointed out, they may 
be largely controlled by proper tillage. Cocklebur, bind- 
weed, Russian thistle, milkweed, and common pigweeds 
all cause the corn-grower trouble. The perennial bind- 
weed, milkweed, and ground cherry are most troublesome 
west of the Great Plains. 

Besides weeds, maize smut and the corn ear-worm are 
the worst enemies to the crop. The smut masses should 
be picked oflF and burned before they burst and spread 
the smut spores. As smut lives over winter in soil or 
manure, it is useless to treat the seed. Clean cultivation 
and rotation of crops are the effective methods of control. 
This is likewise true of the corn ear-w^orm, billbugs, the 
root-louse, rootworms, and chinch-bugs, which do con- 
siderable damage, especially where corn is grown year 
after year on the same land, or w^here culture methods 
are otherwise poor. Fall-plowing and clean farming 
are the best methods of control. Sometimes remedies 
are used advantageously. A treatment for the chinch- 
bug is given in Chapter XVI . 

221. Uses and value. — About nine-tenths of the 
crop enters the food ration of animals without first being 
shelled. For fattening hogs and beef it has no equal. 
Dairymen and horsemen also use much of it as feed. It 
mixes well with alfalfa, which is a flesh and bone builder, 
while corn furnishes energy and fat. Corn alone is not, 
however, a balanced food. 

Green, dried, and canned corn, hominy, corn meal, 
cereal breakfast foods, popcorn, and corn sirup are 
human foods. Corn oil, starch, distiller's grain, cobs, 
husks, and pith find various uses, while the stalks and 
leaves are used for roughage. 

The value in dollars of corn produced in the United 



Corn or Maize 



205 



States exceeds that of any other single crop in this country 
or any other one country, although the world crop of 
wheat and rice surpass the world crop of corn in value 
because little maize is grown in the Old World. 

The great number of uses to which corn can be put 
gives it a value aside from its selling price. It was partic- 
ularly useful to the pioneers of the Mississippi Valley 
because 'it grew on almost unbroken land, even among 




Fig. 61. — A good type of farm Krain bin. 



the stumps. It furnished both animal and human food 
and needed little care. It and meat were the chief foods 
of the early colonists in Jamestown and Plymouth ; it 
accompanied the pioneers until they reached the dry plains 
east of the Rockies, where wheat disjjlaced it. 

222. Storage and marketing. — Because of the high 
percentage of moisture in kernels and cob, the grain 
molds easily in poorly ventilated places ; hence the value 
of the slatted cribs. After being shelled the germination 



206 The Principles of Agronomy 

power is injured by freezing, though the feeding qualities 
are not hurt. On the other liand, the best way to handle 
fodder is to shock it on well-drained ground. The con- 
struction shown in Fig. (31 is a good type of store-house 
for the farm. 

Corn is marketed mostly " on foot," that is, fed to 
animals that are being fitted for market. It does not 
enter into world markets so largely as other cereals, but 
where it does, it is handled much as is wheat except that 
greater precautions are taken in drying. 

For big markets there are grades Nos. 1, 2, 3, and 4 in 
each of three classes — white, mixed, and yellow. 



SUPPLEMENTARY READING 

Corn, Bowman and Crossley. 

The Corn Crops, Montgomery. 

The Book of Corn, Myrick et al. 

Maize, Joseph Biirtt-Davy. 

Cereals in America, T. F. Hunt, pp. 138-279. 

Southern Field Crops, J. F. Duggar, pp. 78-216. 

Manual of Corn .Judging, A. D. Shamel. 

Field Crops, Wilson and Warburton, pp. 47-135. 

Field Crop Production, G. Livingston, pp. 29-98. 

Principles of Irrigation Practice, J. A. Widtsoe, pp. 255-264. 

Cyclopedia of American Agriculture, Vol. II, pp. 398-427. 

U. S. D. A. Yearbook for 1906, pp. 279-294. 

U. S. D. A. Farmers' Bulletins : 

No. 81. Corn Growing in the South. 

199. Corn-growing. 

229. The Production of Good Seed Corn. 

253. The Germination of Seed Corn. 

292. The Cost of Filling Silos. 

303. Corn-harvesting Machinery. 

400. A More Profitable Corn Planting Method. 

414. Corn Cultivation. 

415. Seed Corn. 





Corn or Maize 


207 


537. 


How to Grow an Acre of Corn. 




546. 


How to Manage a Corn Crop in 
Virginia. 


Kentucky and West 


553. 


Popcorn for the Home. 




554. 


Popcorn for the Market. 




617. 


School Lessons on Corn. 





CHAPTER XVIII 

OTHER CEREALS 

Besides corn and wheat, the cereals commonly grown 
in America are oats and barley. Rye is less important 
and rice is confined to a few districts in the South. Buck- 
wheat, though not a true cereal, is grown to some extent 
for grain. Sorghums are more important for forage than 
for grain, and, on that account, are grouped with the 
millets. 

OATS (Avena sativa) 

223. Origin and relationships. — It is little wonder 
that oats were not used for human food until long after 
wheat and barley, Avhen we consider that Avheat has no 
husk covering the kernels and the barley has a much 
thinner one than oats. The Egyptians knew nothing of 
oats, and Greeks or Romans did not cultivate them, 
extensively at least, although they knew them. This is 
not strange, since the grain is primarily adapted for animal 
feed. It is not surprising that oats probably came from 
the region of the great central Eurasian plains — prob- 
ably from the region of Tartary in w^est-central Asia — • 
where cattle and horses had long been cared for. They 
spread over Europe later, especially in the cool, moist 
sections. When introduced into America by the early 
colonists, oats did best in the damp North. 

208 



Other Cereals 209 

Like corn, the oat has but few immediate relatives. 
Nearly all our commonly grown \arieties belong to the 
one species, Avena sativa, though one or two other species 
yield some grain. Like all other true cereals, they be- 
long to the grass family, but to the tribe x'VvencV instead 
of Hordea^, w^hich includes all the other small-grains. 
Two grasses, tall meadow oat-grass and velvet-grass, 
belong to the same tribe as oats. Not only in the 
tribe but in the same genus with the oat is the wild 
oat (Avena fatu a), one of the worst weeds of this grain 
crop. 

224. Description. — The oat plant has a fibrous root- 
system similar to that of wheat except that it does not 
have such a deep rooting habit. The roots spring from 
an underground node generally about an inch below the 
surface — deeper in drier soils — and form a network as 
they penetrate the soil. 

The culms resemble those of wheat except that they 
are usually both thicker and longer, varying from eight- 
een inches to five feet in length, with between three and 
four feet as the ordinary height. Lower joints have the 
power of sending up an erect internode even though the 
one below is lying flat or is inclined. The plant accom- 
plishes this by means of a bent node. 

The leaves grow from the nodes clasping the stem 
nearly to the next node, where they spring outward with- 
out any clasp. The absence of the clasp, together with 
its slightly broader leaf covered with fine hair, enables a 
careful observer to distinguish the young oat plant from 
other small-grains. 

The grain-bearing head of the oat differs widely from 
that of other grains. These bear a compact head, or 
spike, whereas the oat head is a panicle, that is, the 
spikelets are borne on rather long and slender pedicels 



210 The Principles of Agronomy 

holding them far apart. The panicle may be nine to 
twelve inches long and from two to eight inches wide, 
with intermediate measurements most common. 

The spikelets, of which there are from forty to seventy- 
five in a panicle, generally contain two kernels, a smaller 
one being tucked snugly into the groove of a larger one. 
Occasionally, a third grain develops, but this is rare. 
Since single kernels are rather uncommon, the grain 
appears somewhat variant in size of kernel. 

Each kernel is covered with a comparatively thick 
husk, or hull, which breaks away from the interior grain 
when rolled. Some varieties known as hull-less shell 
free from the husk on threshing. A crooked awn occurs 
on the back of the husk instead of at the end as with 
wheat, barley, and rye. In other respects, the structure 
of the grain is almost identical with that of the wheat 
kernel save that the oat grain is proportionately much 
longer and covered with hair. 

225. Distribution. — Oats are naturally adapted to 
those parts of the temperate zone that have a cool, moist 
climate throughout the growing-season. The crop is 
not sensitive to kind of soil except as it regulates the mois- 
ture supply. Heavy soils rich in organic matter favor 
even distribution of moisture in the soil, and, therefore, 
are best. Sandy soil demands frequent applications of 
moisture for high yields. 

The countries that have the favorable climatic condi- 
tions are the best producers. A study of the rainfall 
and temperature of Canada, northern United States, 
central Russia, Germany, Austria-Hungary, France, and 
Great Britain reveals the reasons for their vast oat crop. 
Parts of Scotland and the Scandinavian countries have 
almost ideal conditions, but these areas are too small to 
enable them to count as world producers. For the five 



Other Cereals 211 

years ending with 1910, the nations produced annually 
as follows : 

United States 932,000,000 bushels 

European Russia 865,000,000 bushels 

Germany 583,000,000 bushels 

France 299,000,000 bushels 

Canada . 295,000,000 bushels 

There are vast fields of oats in Manchuria and Ar- 
gentina whose total crops are unreported. The total for 
the world is over four billions of bushels, nearly the same 
as for wheat and corn. These other grains, however, 
exceed oats in total weight. 

The oat-producing areas are spread over the United 
States, but the northern states from New York to Wash- 
ington and Oregon are situated most favorably. The 
leading states in order are: (1) Iowa, (2) Illinois, (3) Wis- 
consin, (4) Minnesota, (5) Nebraska, (6) Ohio, (7) In- 
diana, (8) New York, and (9) Michigan. Western Ore- 
gon and Washington have perhaps the most ideal climates, 
but the district is not large. Many mountain valleys 
in the West which are small and generally isolated also 
have favorable conditions. 

The average acre-yield in the United States has been 
slightly less than thirty bushels, while in Germany and 
Great Britain it is much higher, being in the neighborhood 
of forty to forty-five bushels. By states, the leading 
acre-yields (1902-1911) are as follows: 

Washington 47.6 bushels 

Montana 43.0 bushels 

Idaho 41.7 bushels 

Utah 41.5 bushels 



212 The Principles of Agronomy 

The great producing states all average less than thirty- 
four bushels. A good farmer may expect from sixty to 
more than one hundred bushels. 

226. Varieties. — Oats are classified into groups ac- 
cording to shape of panicle, season of jolanting, color, 
and size and shape of grain. There are spring and winter 
oats. The South grows winter varieties principally in 
order to throw the growing-season in the cool part of the 
year. If the spikelets are borne on short pedicels and 
are all on one side of the culm, they are side oats, or 
" horsemane " oats ; if the head spreads, they are spread- 
ing. These are the oat types. Further classifications 
according to color are described as white, yellow, black, 
red, whitish-yellow, etc. Some varieties are early, others 
late ; some plump, others long-hulled. Seedsmen and 
growers introduce new varieties every year, and old varie- 
ties get new names. A hopeless confusion results ren- 
dering clear grouping and naming impossible. A few 
leading varieties for the country are Big Four, Silvermine, 
Clydesdale, Swedish Select, and American Banner. 

227. Seeding and cultivation. — The preparation of 
the seed-bed for oats is similar to that for wheat. The 
depth of planting varies from one to four inches, just 
under the dry mulched soil. As soon as the land can be 
worked oats may be sown in quantities of from five to 
eight pecks depending on the yield expected and moisture 
supply available. In some districts as little as three or 
four pecks are used ; in others as much as twelve or four- 
teen pecks. Harrowing may begin as soon as the grain 
is up and continue until it would injure the plant. From 
five to thirty inches of irrigation water may be applied 
in parts of the West, in one to six applications. 

228. Harvesting and marketing. — Oats are usually 
cut with the binder, though the header finds occasional 



Other Cereals 213 

use in the regions of small rainfall. Only on very short 
or badly-lodged grain should the farmer use the mower. 
Shocking in the field follows in most regions. Although 
oats should not be cut until after they have reached the 
hard-dough stage, the straw is often so green at this 
stage that the bundles must be piled to permit air to pass 
through the shocks. Setting the bundles in ricks two at 
a time with the second pair just touching the first until 
ten or twelve bundles are in a rick, permits ventilation 
and drying. Careful drying in the shock prevents mold, 
which is detrimental to the quality of the grain. After 
the straw is dry, most farmers stack the oats instead of 
threshing at once. Well-built stacks insure the grain 
against storms until the thresher can be obtained. It 
is asserted by some that stacking seems to improve the 
quality by causing it to " sweat." 

Tight bins to prevent insect injury and to prevent odors 
from stables being absorbed by the grain are essential (Fig. 
61 ) . Although some farmers sell directly from the thresher 
after sacking, most of the crop is stored for feeding pur- 
poses. The part sold makes its way into the ele\'ator 
sA'stem to be handled and graded like wheat, except that 
the groups are classed as white, mixed, and red. White 
is standard. Four grades in each group are made. 

229. Uses. — The most important use of oats is for 
feeding farm animals, such as cattle, hogs, and horses, 
horses being especially fond of them. The hull prevents 
formation of a pasty mass in the stomach ; the grain is 
palatable, nutritious, and easily masticated. 

Rolled oats, or oatmeal, is used as a human food. The 
Scotch formerly used it much. This gave rise to a clash 
of wit between a Scotchman and Dr. Samuel Johnson, 
who said he noticed that in England oats were feed for 
horses, but in Scotland men ate them. The Scotchman 



214 The Principles of Agronomy 

sagely remarked that the best horses grew in England 
and the best men in Scotland. 

Oat hulls, light grain, dust, and impurities — by-prod- 
ucts of oatmeal factories — are used for feed, as is the 
straw, which has more frequent use as bedding for animals, 
although, as roughage, the straw supplemented by some 
hay or grain may carry stock over winter nearly as well 
as Avild hay. Oats alone, or mixed with peas, make fair 
hay if cut before the grain gets hard and while the leaves 
and culms are still green. Peas, of course, increase the 
nitrogen in the ration. 

230. Enemies. — The common weeds all trouble oats. 
Wild mustard is bad ; clean cultivation and rotation, 
clean seed, and spraying with iron sulfate are helpful 
means of eradication. Wild oats {Avena fatiia) are very 
troublesome in some fields long sown to oats, because they 
mature ahead of the crop and shell out before harvest. 
Crop rotation and clean seed are preventives. Since 
wild oats are lighter than the cultivated grain, the fanning 
mill will partly clean the seed. Smut injures oats to 
considerable extent unless the seed is treated. The spores 
enter the oat at blooming time. Oats are treated in 
the same way as wheat, the formalin treatment being per- 
haps the best. 

Rust causes much loss but cannot be remedied directly. 
Indirectly it may be partly controlled by selection of 
early or rust-resistant varieties, by using only well- 
drained land, and by using culture methods to prevent 
lodging. 

The chinch-bug, spring grain-aphis, and the army- worm 
injure the growing crop. Remedies for the chinch-bug 
have been given in Chapter XVI. Clean cultivation and 
fall-plowing help to control the others. It is not usually 
profitable to spray or otherwise treat growing oats for 



Other Cereals 215 

insects. Grain weevils and the Angoumois grain moth 
are best controlled by storage in tight bins. If the bins 
become infested, fumigation with carbon bisulfide will 
kill the insects. Hydrocyanic-acid gas is also effective, 
but extremely dangerous, one full inhalation of it being 
fatal to man. 



BARLEY 



( Hordeum sativum) 



From the earliest dawn of civilization, man has culti- 
vated barley continuously. It has been an important 
crop in all the empires of which we have record. Barley 
belongs to the same tribe as wheat. It has for its near- 
est relative barley-grass (Hordeum jubatum) variously 
called foxtail and squirrel-tail. 

231. Description. — Barley resembles wheat very 
closely, having a fibrous root-system of less extent and 
having stools, culms, leaves, and spikes that are very 
much like those of wheat. The chief apparent differences 
are that it stools less, has shorter straw, and that the 
kernels are usually covered with a lightly-adhering husk, 
which breaks when the grain is crushed. Barley heads 
commonly have beards, although there are a number of 
varieties that lack them ; some lack hulls, and others 
lack both beards and hulls. These, however, are not 
as yet in general use. 

The spikelets are single-flowered, and, therefore, bear 
only one kernel. Three spikelets, however, lie side by 
side. In one type all three spikelets bear grain, while 
in another type only the middle one is fertile, giving 
rise to three rows or to one row, respectively, on each 
side of the spike, — the two sides making six and two 
rows ; hence the name of these types : two-rowed and 
six-rowed barley. 

Two-rowed barley is spring grain, while six-rowed is 



21 G The Principles of Agronomy 

either spring or winter. These varieties of six-rowed 
barley are standard: (1) Oderbrucker, (2) Manchuria, 
and (3) CaHfornia. California Feed and Bay Brewing 
are common in California. Of the two-rowed type Cheva- 
lier and Hanna are most popular. In the Mountain 
States, Tennessee Winter, Chevalier, Utah Winter, and 
Beardless do well. The Southern States grow winter 
varieties in the main. 

232. Distribution and adaptation. — No other grain 
crop withstands successfully such wide differences of 
climate, elevation, and soil as barley. It is cultivated 
from the equator up to the Artie circle, being grown as 
a crop at 65° north latitude. In Peru, at 11,000 feet 
above sea-level it yields well. It is a leading crop on the 
hot, dry plains of Spain and North Africa, though it does 
best on well-drained loam soils with moderate moisture. 
It grows on almost any soil and withstands considerable 
drouth being, therefore, a good dry-farm crop. Since 
it is the most alkali-resistant cereal, it grows well in arid 
regions that have slightly alkaline soils. It is often grown 
on \'irgin land until other crops can be made to grow 
profitably. 

Russia, United States, Germany, Austria-Hungary, 
Japan, Spain, the British Isles, and Canada in the order 
named are the leading producers. California, Minnesota, 
Wisconsin, the Dakotas, and Iowa yield over 80 per cent 
of the crop of the United States. 

In average acre-yields, Idaho is first, with an average 
of about 40 bushels ; Utah second, with 38.5 bushels ; and 
Washington third, with 37 bushels. Good yields are 
from 50 to 100 bushels, though 125 bushels have been 
harvested in some districts under irrigation. 

233. Sowing and cultivation. — For barley as for other 
small-grains, a fine, deep seed-bed is desired. This is 



other Cereals 217 

most easily obtained by fall-plowing followed by early 
spring harrowing. Seed that germinates well should be 
chosen. This is important, because there is often much 
broken grain which cuts down the percentage of ger- 
mination. Careful screening will remedy this. Pure 
varieties should always be used. 

The grain drill does the best seeding, since it controls 
depth and distribution. Two or three inches is the best 
depth usually, but seed can start only in damp soil. Two 
bushels is the common amount of seed for an acre, but 
some farmers sow as much as four. In dry districts 
about one bushel is used. Excessively large quantities 
of seed should be used only for unusual conditions or 
purposes. A little later than for oats, April or May, 
seems the best time for spring sowing, and about the same 
time as for wheat w'hen fall-planting is practiced. 

Barley is usually left uncultivated, though one or two 
harrowings may be profitable in dry sections. Five to 
twenty inches of water in one to four applications increase 
yields markedly in sections where irrigation is practiced. 

234. Harvesting and marketing. — Barley, having a 
shorter growing-season than oats, ripens just ahead of 
them, from May to August, depending on the section. 
Binders usually do the harvesting, leaving the grain to 
be shocked and stacked. Headers and combined-har- 
vesters are used to some extent. Shocks of barley to be 
used for malting are commonly thatched with loosened 
bundles to prevent staining, which injures the grain by 
discoloring the malt and giving it a bad taste. The thatch 
of the shocks is threshed separately and used for feed. 
Malt barley also requires extra care in threshing to pre- 
vent breaking or tearing the husks, either of which causes 
slow germination. Rapid germination is very desirable 
since, to get a strong malt, all kernels must germinate 



218 The Principles of Agronomy 

within forty-eight hours of each other. The careful 
removal of dirt and weed seed much improves the grain 
for both feed and malt. 

Careful storage is essential for the same reason as that 
stated for careful shocking and stacking. Since malt 
barley is all sold, it must be carefully handled. Two- 
thirds of all barley finds its way into the market by a 
course similar to that of wheat. There are two groups 
of grades — " barley " and " rejected." In each there are 
grades 1, 2, 3, and 4. 

235. Enemies and uses. — The insects that attack bar- 
ley are chinch-bug, grain-aphis, and Hessian fly. Reme- 
dies, where pests are present, are fall-plowing, rotation, 
and clean farming. Insects in the bin are controlled by 
carbon-bisulfide fumigation. Loose and closed smuts of 
barley are prevented by the formalin or hot water treat- 
ments, respectively. Where the rusts are present, selec- 
tion of stiff-strawed, early-maturing varieties, and plant- 
ing on well-drained land not so rich in organic matter 
as to cause lodging, are the methods of control. 

For hogs, barley is a splendid concentrate, producing 
a good quality of pork. For sheep, cattle, and poultry, 
it is usually crushed and mixed with oats or bran to lighten 
it. It is much used on the Pacific Coast for horses. In 
the Latin countries of Europe, barley is used for bread, 
but not so much as formerly. In the United States, the 
kernel with husk removed is used as pearl barley in soup. 
It forms a part of the manufactured cereal foods. 

The by-products are used in various ways : (1) the 
straw for bedding and feed, although the beards, or awns, 
lower the feeding value ; (2) hulls and broken grain for 
feed products ; and (3) malt sprouts and brewers' grain 
(remnants from malt industry), which are high in protein, 
for feed, particularly for dairy cows. In the West and 



Other Cereals 219 

South, some barley is cut green for hay. Hull-less barley 
mixed with peas, cowpeas, or vetch makes fairly good hay, 
and a good pasture for hogs. 

The value of barley like that of oats and corn is closely 
related to the livestock industry. Barley and bran are 
high in protein and mix well with corn, which is high in 
carbohydrates. There may be a growing use for barley 
as one of a number of grains in a mixed grain ration. An 
increased number of choppers on the farm should widen 
its use. 

As a world crop, barley yields only one and one-half 
billion bushels and ranks far below the other grains. In 
the United States barley ranks ninth, oats sixth, wheat 
second, and corn first in importance. 

RYE (Secale cereale) 

236. Description and distribution. — Rye came into 
Europe later than Roman times and spread rapidly 
over the northern and central parts of the continent from 
Spain to Central Asia. It is more closely related to 
wheat than to any other crop. Another species occurs 
in Austria-Hungary and Russia. 

The root-s>'stem is fibrous, but its rooting habit is not 
as deep as that of wheat. It stools considerably, grow- 
ing longer, finer, tougher culms than other small-grain. 
It has few leaves and long spikes, the glumes of which 
always bear beards. The kernels are naked, long, slim, 
and dark-colored. Rye has the power of sending up 
new culms after being cut, a power possessed only to a 
slight extent h\ other cereals. There are but few varie- 
ties of rye, because cross-fertilization takes place so readily 
in the field that all strains are mixed. 

Russia produces more than half and Germany more than 



220 The Principles of Agronomy 

a fourth of the crop of tlie world. Other countries fol- 
low in this order : Austria-Hungary, France, and the 
United States. In the United States, (1) Pennsylvania, 
(2) Wisconsin, (3) ]\Iichigan, (4) Minnesota, and (5) 
New York produce most of the crop. Rye, grown as a 
winter crop in Alaska, is more frost-resistant than even 
wheat or barley. It can grow on poorer soils than nearly 
any other crop ; it is also drouth-resistant. 

237. Handling the crop. — Fertile soil and a good 
seed-bed increase the yield. It is usually sown with 
drills in fall or spring at the rate of five or six pecks ; dry- 
farms sometimes require only two or three pecks and 
pasture as much as eight pecks. It grows best with the 
shallowest planting that will enable it to sprout. Har- 
rowing encourages stooling, but irrigation does not pay 
ordinarily, because yields are too small. Harvesting 
and threshing methods are the same as for wheat, oats, 
or barley. 

Ergot, a fungous disease, is the only serious enemy. 
It is poisonous to cattle in addition to injuring the yield. 
Cleaning the seed and rotating each year help to o\'er- 
come it. Insects trouble but little ; there are no special 
weeds. 

238. Uses. — Rye bread feeds a vast number of the 
people in Russia, Germany, Norway, Sweden, and other 
parts of Slavonic and Teutonic Europe. It is yielding 
place to wheat as human food. As animal food, the grain 
is used mostly in mixed rations. It is better for hogs 
and horses than for other animals. The grain also 
forms part of the mixtures for malt, and the by-products 
are used as animal food. When green, the plant furnishes 
second-class hay, or, if plowed under, a poor green 
manure. The straw is poor feed on account of being 
tough. Fall-planted rye is sometimes pastured by cattle 



Other Cereals 221 

or sheep. In parts of Europe the straw is more vahiable 
than the grain, being woven into mats, carpets, plates, 
dishes, baskets, boxes, trunks, and various trinkets and 
articles of apparel. Rye cannot, at present, be an im- 
portant grain crop in the United States. In Europe, it 
ranks high ; in the United States, it is only eleventh ; as 
a world crop, it is smaller than wheat, corn, oats, and rice. 



RICE {Oryza sativa) 

239. Description and distribution. — Rice has fed 
nearly half of the population of the earth for about 4000 
years. In 1694, a trading vessel carried the first rice 
to South Carolina. It spread slowly until the last thirty 
years, during which time it has become a valuable crop 
in Louisiana, Texas, Arkansas, and Central America. 

The nations producing it rank as follows : 

India 70 billion pounds 

China 50 billion pounds 

Japan 18 billion pounds 

All Europe 12 billion pounds 

The high price — about three cents a pound — gives 
it a greater cash value than any other crop. 

The plant slightly resembles oats, save that the panicles 
are closed. The grain is covered with a husk called paddy 
that must be removed before it is used for food. Upland 
and lowland are the two types, lowland requiring to be 
flooded a large part of the growing season, while upland 
is not irrigated. 

240. Uses. — The most important use of rice is as 
food for man. Machinery removes the hull ; rollers 
covered with sheepskin, one going faster than the other. 



222 The Principles of Agronomy 

polish the grain. The flour or poHsh is valuable stock- 
feed. Asiatics omit the polishing, thereby saving much 
food value. Rice straw has some feeding and weaving 
value. 

EMMER ( Triticum sativum dicoccum) 

241. Description and use. — Emmer is a sub-species of 
wheat and differs from it chiefly in that in threshing the 
spikelets retain the kernels in the glumes. It is grown 
rather extensively in Russia, southern Europe, and east 
central Africa. During the last thirty years, dry-farm 
sections of the United States and sections that cannot 
profitably grow oats for feed produce constantly increas- 
ing quantities. 

Rust- and drouth-resistance are qualities recommending 
its use. Both winter and spring varieties are grown — 
winter in the West and spring in the East and South. 
Black winter emmer is the most commonly grown variety. 
It is planted, as are oats, at the rate of from four to twelve 
pecks an acre. It yields from twenty to seventy bushels. 
The husk covering the grain prevents the formation of 
heavy, pasty masses in the stomachs of animals, thereby 
aiding digestion. In this respect it is like oats. 

BUCKWHEAT (Fagopyrum esculentum) 

242. Description, distribution, and uses. — Buckwheat 
is not a true cereal, since it belongs to the dock, instead 
of to the grass family. It came from Manchuria to New 
England, New York, and Pennsylvania, where it is still 
largely used as a catch-crop when other crops fail and it 
is too late to replant them. 

The plant has a tap-root ; a branched stem two or three 
feet in height, each branch ending in a flat-topped cluster 



Other Cereals 223 

of white flowers ; and broad leaves something like those 
of the morning-glory. The seed is dark gray or brown, 
angular, and covered with a rather strong, loose hull. 
The growing-season is so short that a fie'"^ may be planted 
as late as July 1, and yet mature, its yield is small 
but it pays better than no crop on la ' .vhere some other 
crop has failed to begin growth. It is cut with a binder 
and shocked in order to dry the succulent stems. Buck- 
wheat is famous as the source of pancake flour. It has 
some value for hogs and poultry and the straw is some- 
times used for feed and bedding, but it is rather coarse 
and unpalatable. 

SUPPLEMENTARY READING 

Cereals in America, T. F. Hunt, pp. 280-410. 
Fiekl Crops, Wilson and Warburton, pp. 175-268. 
Field Crop Production, G. Livingston, pp. 145-193. 
Southern Field Crops, J. F. Duggar, pp. ]-31, 68-77, 217-230. 
Cyclopedia of American Agriculture, Vol. II, pp. 202-206, 485-494, 

559-564. 
U. S. D. A. Farmers' Bulletins : 

No. 139. Emmer : A Grain for the Semi-f Id Regions. 

395. Sixty-day and Kherson Oats. 

420. Oats : Distribution and Uses. 

424. Oats : Growing the Crop. 

427. Barley Culture in the Southern States. 

436. Winter Oats for the South. 

443. Barley : Growing the Crop. 

466. Winter Emmer. 

518. Winter Barley. 



CHAPTER XIX 

PO TA TOES (Solanum tuberosum) 

Of the crops designated as " root crops," potatoes and 
sugar-beets are by far the most important. The methods 
by which they are produced, depending much on hand- 
labor and requiring fertihzers and constant attention, 
demand that these crops be handled on small areas in- 
tensively farmed. There is a noticeable absence of 
machines that cover ten to forty acres in a single day, 
although there is a promise of implements that will modify 
methods of culture. Planters, cultivators, and diggers 
have done much to relieve the farmer of slow and ex- 
hausting hand-labor. Field conditions in potato-growing 
are shown in Figs. 62 to 65. 

243. Origin. — The potato was growing wild in the 
valleys of Peru and Chile when the Spaniards first visited 
these countries about 1542. Another kind of potato was 
found in Mexico and southern Colorado. This useful 
plant made its way into Virginia in time to be carried 
to England and Ireland by Raleigh's expedition in 1586. 
In Ireland it did so well that it soon became the princi- 
pal food crop. Meantime, the Indians and whites in 
the neighborhood of Virginia gradually increased their 
dependence on it until, by the first of the eighteenth cen- 
tury, they used it generally. By the middle of the cen- 
tury, it had spread into the parts of Europe favorable 
to its growth and gained larger and larger footholds on 

224 



Potatoes 



225 



account of its great acre-yields. In thickly populated 
districts, just such a food crop was needed. 

244. Relationships. — There are about sixteen hun- 
dred species in the potato family, nine hundred of them 
in the same genus, but only six out of all this number 
bear tubers. Besides the potato, only Solanum Com- 
mersonii is important. It is disease-resistant, but yields 
poorly. Among the immediate relatives of the potato 




Fid. 02. — Potato planter at work: notched-wheel type. 



is the tomato, which is so closely related that parts of one 
plant may be grafted on the other. Tobacco, nightshade, 
henbane, and belladonna also belong in this family. 

245. Description. — The plant originally propagated 
itself by means of seed, but it has reproduced by tubers 
that contain buds, or " eyes," for such a long time that 
the seed is seldom, or never, considered. The buried 
" set," as the cut piece of tuber is called, sends out a 
stem which bears leaves after reaching sunlight. The 
Q 



226 



The Principles of Agronomy 



length of this underground stem depends on the deptli 
of planting. At various places on this stem, new branches, 
or stolons, grow horizontally outward bearing tubers 
at the end. Meanwhile, from two to four roots grow from 
the upright stem just at the base of tuber-bearing sto- 
lons. 

By the time of maturity, the fibrous roots have spread 
for six or eight inches and have extended four or five feet 




Fig. 63. — Constant cultivation is necessary for good potato yields. 



into the soil if it is loose and well-drained. Tubers from 
one to thirty in number, varying from the size of a pea to 
six pounds, have developed in a single hill. About six 
or seven potatoes as large as the double-fist are preferred. 
The angular stem, from one to five feet in length, usually 
about two or two and a half feet high, stands upright or 
droops across the open space, depending on the variety 
and soil conditions. The leaves are compound with 
small leaflets growing in the axil and scattered irregularly 



Potatoes 227 

between the thick, pointed, oval leaf-parts, which are 
from one to three inches long. 

Buds or eyes are borne sparsely at the stem end and 
close together at the bud end. A string passed round 
the tuber and held in position with a pin in each eye 
shows the spiral arrangement of eyes. Cross-sections 
of a tuber show three nearly concentric, and one irregular 
part. The outermost, the external cortical, is poor in 
starch and so thin as to be almost entirely removed in 
peeling. Then comes a thicker layer, rich in starch, 
called the internal cortical, surrounding the external 
medullary, also rich in starch. The dark colored core, 
the internal medullary, is watery and low in starch. A 
potato that contains proportionately large external 
medullary and internal cortical is desirable on account 
of high starch content, which gives the potato the quality 
of mashing readily when cooked. Potatoes that are 
yellow and soggy after cooking are undesirable in America, 
where they are baked or boiled, but are highly prized by 
the French, who serve them fried. 

246. Varieties. — Potatoes are usually classed as early 
and late, although color, depth or arrangement of eyes, 
and roughness of skin might each give rise to a grouping. 
The early varieties yield less, but mature in about one 
hundred days bringing higher prices on account of reach- 
ing market early. Late potatoes comprise the bulk of 
the crop wherever large acreages are grown, except near 
city markets. Requiring about one hundred and thirty 
days to ripen, they cannot reach the early market, but 
are allowed to grow late in order to give the greatest pos- 
sible yield. 

Varieties originate either by variation in hills planted 
by sets, or from mixtures arising from the seed-planted 
hills, which always contain several distinct kinds of tubers. 



228 The Principles of Agronomy 

The Pearl, for example, comes from a bud variation of 
Blue Victors, while the Burbank was found in a seed-sown 
hill. Often old varieties are given new names in order 
to sell them. Some confusion in different sections can- 
not be avoided, but should be as nearly eliminated as 
possible. 

Bliss Triumph, Peachblow, Eureka, Early Ohio, and 
Early Rose are common early varieties. Rural New 
Yorker, Sir Walter Raleigh, Carman No. 3, Green Moun- 
tain, and Burbank are popular in the Northern States. 
In the Mountain States, Pearl, Idaho Rural, Rural New 
Yorker, Mortgage Lifter, Netted Gem, Carmen, Peerless, 
Majestic, and Freeman, are profitable yielders under 
irrigation. 

247. Distribution and adaptation. — A cool, even grow- 
ing-season without severe frost, and a loose, warm soil 
containing medium moisture throughout the season, are 
the conditions most favorable to potato-growing. Ideal 
conditions in Scotland, Germany, and Russia produce 
almost unbelievable yields. Eighteen hundred bushels 
to the acre was grown on the seed-farm of Lord Rosebery 
near Edinburgh. Scandinavia also has a good, climate 
for potato production. 

The large countries that lie in this section of Europe 
are all heavy producers, ranking as follows in total pro- 
duction : (1) Germany, (2) Russia, (3) Austria-Hungary, 
and (4) France, with the United States fifth, and Great 
Britain sixth. 

Out of the five billion bushels produced, Germany grows 
about one and seven-tenths billions, while the United 
States produces only one-third of a billion bushels. 

The acre-yield is 197 bushels in Germany ; 186 in the 
British Isles; 140 in Austria-Hungary; 134 in France; 
100 in Russia ; and 90 in the United States. Maine leads 



Potatoes 



229 




230 



The Principles of Agronomy 



all states, with 225 bushels. Some other leaders are Idaho, 
200 bushels; Montana and Utah, 180 bushels; Wash- 
ington, 170; Colorado, 160; and Wyoming, 145. All 
except Maine are in the irrigated district. As total pro- 
ducers, the states rank: (1) New York, (2) Michigan, (3) 
Maine, (4) Wisconsin, (5) Ohio, and (6) Illinois, with 
only Maine averaging more than ninety-two bushels. 
In the East, four hundred bushels is a good acre-yield. 



■ 




. 














a 


HiiHI 


a 


1 




B 




IK 




1 


1 


" 


u -r'-iJ 







Fi(i. G5. 



Great potato-producing section, Aroostook County, Maine. 



while in the irrigated district seven hundred to eight 
hundred bushels are produced occasionally, and one 
thousand bushels under especially favorable conditions. 
Good farmers may expect from three hundred to five 
hundred bushels an acre. 

248. Preparation of land. — Farmers can well afford 
to spend extra time and labor preparing a good seed-bed 
for potatoes. Heavy applications of farm manure pay, 
though it is well to apply it to the previous crop or in the 
fall preceding potatoes in order that it may be well de- 
composed. This helps to form a fine, moist seed-bed. 
Coarse manure opens up the soil permitting excessive 



Potatoes 231 

drying, which is detrimental. The high water-holding 
capacity of soils due to manuring increases yields materi- 
ally. To serve efficiently the organic matter must be 
thoroughly mixed with the soil. Old decomposed manure 
does this very well, but fresh manure sometimes does 
more harm than good. Moreover, too much coarse 
organic matter in limy soils aggravates potato scab. 
Where commercial fertilizers are used, potatoes respond 
readil}" to potash. 

Deep fall-plowing is essential in loosening the seed- 
bed and in holding water for the next season. A rough 
surface left over winter prevents any run-off and gives 
frost an opportunity to disintegrate clods and liberate 
plant-food. A disk completes the fining process long 
before a plow could be used. This hastens the warming 
of the soil and reduces the enormous evaporation of early 
spring by the formation of a mulch. Another disking, 
or one or two harrowings to keep the mulch loose, will 
leave a deep, mellow, moist seed-bed ready for planting. 

249. Seed. — Some varieties have much higher yield- 
ing possibilities than do others ; therefore, the variety 
chosen is important. One disturbing factor in choosing 
potato seed is that some districts cannot use home-grown 
seed. The North ships to the South practically all the 
seed used there. Arizona also imports seed potatoes. In 
the West, some growers have small farms in mountain val- 
leys which furnish seed for their large farms in the lower 
valley. In most cases selected home-grown seed is best. 

After a good variety is chosen, the next most important 
thing to consider is disease, which may reduce the yield 
from 5 to 50, or even 100 per cent. Most diseases can 
be detected by examining the tubers. Absolute freedom 
from disease, if possible, is desired. 

Sometimes varieties deteriorate, or " run out." This 



232 The Principles of Agronomy 

need not happen if proper selection is practiced. There 
is a tendency to use or sell the marketable potatoes, 
thus leaving the small ones for seed. It has been found 
that potato hills vary a great deal not only in the number 
of potatoes they produce, but also in the kind. Some 
hills have from four to eight tubers of very much the same 
size and shape containing no very large ones and not many 
small ones; others one large potato and a nimiber of 
small ones; while still others consist almost entirely of 
small tubers. Since both very large and very small 
potatoes are undesirable on the market, hills with a fair 
number of medium-sized tubers are most desirable. 

A set from any potato in the hill tends to produce a 
hill like the parent hill. A big potato from a poor hill 
is not so good seed as a smaller one from a good hill. It 
seems that any potato in a hill is as good for seed as any 
other and if such is true, there is no objection to using 
the small potatoes from desirable hills. If, however, 
small tubers from a bin or pit are used, most of them will 
be from poor hills. 

Seed selection is so simple that every farmer can fol- 
low it successfully. The farmer will know which part 
of the patch has the healthiest potatoes. With a dig- 
ging fork he can take out a few hundred hills, piling them 
separately. By examining the piles, he can easily select 
hills that contain the type he desires. For more techni- 
cal work, some may desire to study the plants all summer. 
When such is the case, a peg may be driven close to the 
hills that promise well. 

Selected seed requires careful storage, and protection 
from frost and heat. Boxes or crates holding from forty 
to seventy pounds are convenient, since this method 
prevents decay of any great number of tubers, and per- 
mits quicker shipment. 



Potatoes 233 

Where an early crop is desired, the seed may be soaked 
for forty-eight hours in lukewarm water. This seems 
to hasten growth a number of days. Another method is 
to expose well-kept tubers to the light for a few days 
until green sprouts show in the eyes. The long sprouts 
that grow when the storage place is too warm sap the 
strength of the seed, but are useless because they break 
off in planting. 

250. Cutting and planting. — How large to cut the 
sets is a question of considerable importance. Sometimes 
whole potatoes are used ; but usually cut sets varying 
from half potatoes to one-eye pieces are planted. On a 
mellow seed-bed, small sets may be used, but it does not 
pay to cut the pieces too small. A deep, two-eye set 
serves for ordinary planting. No core should be left 
after the eyes are cut out. The whole tuber seems to 
resist diseases in the ground more than the cut sets, in 
some instances at least. Careful hand-cutting has the 
advantage of insuring an eye in every set. Whatever 
the method, cutting should be done near the time of plant- 
ing. Sometimes, a machine that pushes the potato 
against stationary knives is used. 

There are several methods of planting. Many acres 
are planted behind the plow that turns under manure; 
the sets are not always thrust into the loose soil on the 
side of the plow-furrow but are too often dropped on 
the hard furrow bottom. Another way is to make fur- 
rows in prepared soil, drop the potatoes by hand, or by 
hand-planters, and then cover them. There are two 
kinds of machine planters in use, the picker type and the 
notched-wheel type. The picker takes the sets out of 
a hopper with spikes which are fastened to a revolving 
vertical disk and drops them down a pipe into the furrow. 
The other machine does the work by elevating the sets 



234 The Principles of Agronomy 

to a notched, revolving, horizontal disk which is watched 
by a man, who fills empty notches or removes a set if two 
are in one place. When the notch passes over the delivery 
spout, the set drops through. The picker machine re- 
quires only the driver, but misses from 5 to 20 per cent ; 
the other requires two men and can be made to miss less 
than 1 per cent. The horse-power planter furrows, drops, 
and covers five or six acres a day. It is estimated that 
a farmer can afford a machine planter if he grows six 
acres or more. 

There is no fixed depth for planting. From two to 
six inches is usual, while three to four is most common. 
Light, warm soils permit and require greater depths. 
Growing tubers should be surrounded by loose soil and 
yet not be so near the surface as to expose any to sunlight, 
which will injure them by causing chlorophyll to develop. 

Early potatoes are planted as soon as possible, and late 
ones usually in May, though in some districts, early June 
is the best time. In the South, January to April is the 
time; a second crop is planted in some districts in July 
or August. The distance between hills and rows varies 
from twelve to twenty inches. Ten to fifteen bushels 
will plant an acre. 

251. Treatment during growth. — If the ground crusts, 
harrowing before the potatoes are up may help them 
through. About two weeks later when the vines are 
three or four inches tall, another harrowing is advisable. 
The cultivator may begin work in another week or two, 
mulching deeper toward the middle of the space between 
rows if irrigation water is to be applied. This prepares 
for a furrow. 

From five to twentv-five inches of irrigation water 
may be applied in one to five or six applications. Every 
two weeks, or so soon as possible after each irrigation or 



Potatoes 235 

rainstorm, the cultivator should be used to stir the soil, 
gradually leaving a wider space untouched as the vines 
increase in size. This may be continued until the plants 
would be injured by the horse or cultivator. Then suffi- 
cient hand-hoeing to control weeds is necessary. 

252. Harvesting and marketing. — Early potatoes are 
harvested as soon as they are large enough to be put on 
the market ; the late crop is left as long as is consistent 
with approaching winter or maturity, in order to gain 
all possible advantage from the cool, autumn growing- 
season. Small patches are frequently dug with forks 
or turned out with the plow ; but diggers are gaining in 
importance, particularly for large fields. A shovel blade 
passes under the potatoes and elevators carry the tubers 
upward at the same time shaking off the dirt. Some 
machines have rotating arms that throw out the vines; 
some also sort the tubers. The potatoes are picked up 
by hand behind the fork, plow, or digger, and sacked, 
boxed, or loaded loose into wagons to be hauled away and 
sold or stored in pits or cellars. 

The potatoes that are sold go either to consumers 
directly, or to jobbers who ship or distribute them to 
retailers. Potato prices vary so much that it is hard to 
tell whether to sell at harvest or to store for the winter 
and spring markets. Because of its perishability, the 
crop is waste in spring if it cannot be disposed of. Some 
growers sell half and store half ; others belong to coopera- 
tive associations that assist in marketing. Wherever ship- 
ping is practiced, carload lots of single varieties sell to 
the best advantage. Careful sorting and grading also 
help sales and prices. Both boxes and sacks are used 
for shipping. 

253. Storage. — The part of the crop that is stored 
goes into pits loose or into cellars loose, in sacks, or in 



236 The Principles of Agronomy 

boxes. Pits cost less than do cellars. They ordinarily 
consist of a trench a few inches deep in which is set a 
rick heaped-up with potatoes and covered with straw 
and earth. As winter approaches, they are covered with 
more straw and earth. A stove-pipe through the cover- 
ing to aid in ventilation may be closed with cloth in 
freezing weather. Pits should be emptied when once 
opened, the potatoes being sold or removed to a cellar. 
The important points in storage are : (1) to keep the 
temperature above freezing, but not over 40° F. ; (2) 
to provide ventilation ; (3) to examine for disease and 
condition of keeping ; and (4) to be able to remove con- 
veniently a part without disturbing the others. In these 
respects cellars excel pits ; boxes are better than sacks ; 
and sacks better than liins of loose tubers. 

254. Weeds and insects. — All common weeds trouble 
potatoes, though there are none that are troublesome to 
potatoes alone. The intensive culture demanded by the 
potato should control any weed. Of the insects, the 
flea-beetle {Epitrix cucumeris) bores holes in the leaves 
allowing the blights to enter. Arsenate of lead aids 
in lessening the injury. More injurious is the potato 
beetle or Colorado potato beetle, which eats the leaves 
about the time of bloom. Paris-green spray, at the rate 
of one pound in one hundred twenty gallons of water ; 
or arsenate of lead, six or eight pounds in one hundred 
gallons of water lessens this injury. Potato worms, 
potato stalk weevils, grasshoppers, and June beetles 
do lesser injuries. They are generally controlled by 
clean cultivation and rotation. 

255. Diseases. — Potatoes are attacked readily by par- 
asitic organisms, which often cause a loss in a district of 
from one-fourth to one-half the crop, sometimes completely 
destroying it. Late and early blight, Fusarium wilt 



Potatoes 



237 



(Fig. 66), Rhizoctonia, blackleg, and scab are found in 
various parts of the country. 

Late blight (Phytophthora infestans), althoughnot preva- 
lent in the West, is the most serious disease in the East. 
It caused the Irish famine of the " forties," during one 
year of which 300,000 people perished and thousands 
emigrated to America. The disease attacks the vines 
and tubers causing the tubers to rot. Damp weather 




Fig. 60. — Potatoes killed by Fusarium wilt. 



seems to encourage it. Injury is lessened by spraying 
with Bordeaux mixture, which is made by dissolving 
five pounds of quicklime in twenty-fi\'e gallons of water, 
and five pounds of blue vitriol in twenty-five gallons of 
water and mixing the two solutions. There should be 
sufficient lime to prevent burning. 

Early blight (Alternaria solani) does its damage earlier 
in the season than late blight. It attacks the vines, turn- 



238 The Principles of Agronomy 

iiig them yellow and reducing the yield. Bordeaux 
mixture spray aids in its control. 

Dry rot (Fusarium oxysporum) is widespread. It at- 
tacks the stems, causes wilting by clogging the tracheal 
tubes, and grows downward into the tuber, forming a dark 
ring which shows in a thin cross-section of the stem end. 
All seed showing infection should be discarded. Since 
this disease lives in the ground, rotation is essential to its 
control. 

Rosette, or Rhizoctonia (Corticium vagum), is common 
and may be noted by black spots oh the potatoes. It 
attacks the stems from the outside and eats through the 
phloem, thus holding the food in the vine. This causes 
rosettes of leaves and small worthless tubers to form on 
the vines. To discard infected seed and to soak the 
tubers in a mercuric bichloride (HgCl2) solution 1 part to 
1000 of water are the remedies used. Because the disease 
lives several years in the soil or on other plants, clean 
farming and rotations are necessary. 

Scab {Oospora scabies) attacks the tuber causing a 
rough appearance resembling a scab. As it survives in 
the soil, rotations are beneficial. The seed treatment 
is soaking two hours in formalin solution one pint to thirty 
gallons of water. Fresh manure and lime seem to encour- 
age the disease. 

Blackleg {Bacillus phytophthorus) attacks the vine, 
causing wilting, and the tuber, causing rot. Rotations, 
clean ground, and little water after an attack are recom- 
mended as means of control. 

Seed selection for resistant strains, discarding infected 
seed, long rotations, and seed treatment are the most 
hopeful means of keeping up yields. Neglect is likely 
to cause the ruin of the potato industry in some localities. 

Second growth is the production of new tubers when 



Potatoes 239 

water is applied after drouth. The potatoes cannot get 
large and they are poor in quality. Internal brown 
spots are found in the interior of some potatoes, especially 
in the Early Ohio. It is probably not a disease, but a 
physiological condition which injures the odor and flavor 
of the potato but not its seed value. It is caused by 
drouth in some cases. 

Growing potatoes during tuber formation are very 
sensitive to sudden changes of temperature. Heavy 
storms and irrigation, at times, cause abnormal conditions 
that are not easily explained. 

256. Use and value. — The most important use of 
potatoes is for human food. Large parts of Ireland, 
Germany, France, Austria-Hungary, and Russia are 
dependent on the potato as the principal food product. 
A general crop failure would probably cause a famine in 
some districts. The per capita consumption is twenty 
bushels in Germany, as against five and one-half in the 
United States. Desiccated potatoes are valuable foods 
in tropical and frigid zones. Potatoes are sliced and 
toasted to make potato chips. In addition, potatoes are 
used some for stock-feed and for the manufacture of 
starch, sirup, alcohol, and dextrin. They are sometimes 
used for silage. Since potatoes are about three-fourths 
water, the total dry matter of the crop is less than that 
of the leading cereals, although in gross weight the yield 
exceeds any one of them. 



SUPPLEMENTARY READING 

The Potato, Samuel Eraser. 

The Potato, Grubb and Guilford. 

Field Crops, Wilson and Warbiu-ton, pp. 422-443. 

Field Crop Production, G. Livingston, pp. 358-369. 



240 The Principles of Agronomy 

The Potato Industry of Colorado, Colo. Bui. No. 175, Fitch, Bennett, 

and Johnson. 
Cyclopedia of American Agriculture, Vol. II, pp. 519-529. 
American Irrigation Farming, W. H. Olin, pp. 170—188. 
U. S. D. A. Farmers' Bulletins : 

No. 91. Potato Diseases and Treatment. 

295. Potatoes and the Root Crops as Food. 

320. Potato Spraying. 

365. Potato Growing in Northern Sections. 

386. Potato Cultiu-e on Irrigated Farms of the West. 

407. The Potato as a Truck Crop. 

410. Potato Culls as a Source of Industrial Alcohol. 

533. Good Seed Potatoes and How to Produce Them. 

544. Potato-tuber Diseases. 



CHAPTER XX 
ROOT CROPS 

The term " root crops " is applied in a loose way to 
those forage crops not grasses or legumes. In addition, 
a number of plants used for other purposes, such as sugar- 
beets, are included. The classes of root crops are : (1) 
the beets, (2) turnips and rutabagas, (3) carrots. 

These plants are usually biennial. In general a fleshy 
root develops the first season, which if left in the ground, 
sends up seed-stalks the next year and matures seed 
largely from plant-food stored in the root. In parts of 
Europe, root crops are grown extensively for stock-feed, 
and enter into farm rotations commonly. In America, 
they are just gaining foothold. 

Beets belong in the family Chenopodiaceae, which has 
for some of its other members spinach, and many weeds, 
such as common white pigweed, or lamb's quarter, Aus- 
tralian and other salt-bushes, white tumbleweed, and 
Russian thistle. In the species are four principal groups : 
(1) the chard, which is used for greens and which is grown 
in gardens only; (2) common red garden-beet, used for 
food, but not grown as a field crop other than in truck- 
garden districts ; (3) mangel-wurzels, used for stock-feed ; 
and (4) sugar-beets, used in sugar manufacture and for 
stock-feed. 

SUGAR-BEETS 

257. History. — In 1747 Professor Marggaf, a Ger- 
man chemist, discovered a method of extracting sugar 
R 241 



f> 



242 



The Principles of Agronomy 



from the sugar-beet. In 1805 one of his pupils, Achard, 
began the sugar industry by starting a factory in the 
German province of Silesia. Six years later the French 
planted 90,000 acres of beets at the order of Napoleon, 
who appropriated a large sum of money for instruction 
in schools and to assist in building factories. By 1825, 
it had become an established industry in France; by 




Fig. 67. — Thinning sugar-beets, Germany. 

1835, the Germans, realizing how much the French had 
gained both from the industry and improved culture 
methods, began beet-growing on a commercial scale. In 

1836, France produced 40,000 tons of sugar and Germany 
1400 tons. Soon the German output led, as it has done 
ever since. Beet-culture spread rapidly into other parts 
of Europe and finally extended to the United States 
about 1830, but it did not become important here until 
1879, when a factory was built at Alvarado, California. 
Since that time, growth has been rapid and regular. In a 



Root Crops 243 

century, the culture of sugar-beets has grown to such an 
extent that half the sugar produced in the world is beet 
sugar, Europe producing more than nine-tenths of the 
total. Sugar-beet conditions are shown in Figs. 67-69. 

258. Description. — In general appearance, the beet 
is whitish and shaped like a long cone, broadest just 
below the crown from which about a dozen leaves grow 
out in thick clusters. These vary in length from six 
inches to two feet, and in width from two to six inches. 
On opposite sides of the root are two depressions or dim- 
ples, usually slightly spiral in shape. From the dimples 
and from the central tap-root of the beet, fibrous feeding 
roots branch off, gathering food and moisture from a 
rather large area, sometimes to a depth of five or six feet. 

Cross-sections of a beet show a series of concentric 
alternating rings, mostly of soft and firm tissue. The 
compact rings are thought to be richer in dry-matter and 
sugar. A longitudinal-section shows (1) the crown, which 
is rough, slightly greenish in color, and watery, and (2) the 
root, which contains the sugar. The root should taper 
slowly, keep broad to considerable depth, and be single ; 
branching roots are objectionable. The concentric rings 
show in straight lines converging at the bottom. The 
crown, removed in topping, is a part of the stem, as shown 
by the leaves growing from it ; the lower part is an en- 
larged root that should wxigh from one to one and 
one-half pounds in order to meet the demands of factory 
operators. During the second year, seed-stalks, from 
two to four feet tall and considerably branched, bear 
from one-fifth to two pounds of seed for each mother 
beet. 

259. Adaptation and distribution. — Beets, like pota- 
toes, do best in cool, moist climates that have long grow- 
ing seasons. They are not sensitive to frost, being grown 



244 The Principles of Agronomy 




Fiu. 68. — Sugar-beets require a vigorous leaf growth. 



Root Crops 245 

extensively in climates too cool for corn. Well-drained 
soils, varying through sands and loams to clay loams, 
are used ; soils containing small quantities of alkali also 
yield satisfactory crops. Salt, however, causes some 
difficulty in the extraction of sugar. Abundant sun- 
shine is necessary to build up the sugar which is entirely 
carbohydrate and, therefore, the result of photosynthesis. 
Where the soils are deep and can be drained, where mois- 
ture is supplied by rainfall or irrigation, and where sun- 
shine is abundant, sugar-beet growing can become an im- 
portant industry. 

Northern United States from Virginia to Canada is 
adapted to the culture of sugar-beets, though but small 
parts of the section now produce them. The following 
states named in the order of their sugar production 
excel the others in this industry : Colorado, California, 
Michigan, Utah, Idaho, and Wisconsin. These states, in 
1913 contained four-fifths of the factories. The industry 
is capable of almost indefinite expansion. 

In Europe, the beet-growing nations are the same that 
lead in potato production, namely, (1) Germany, (2) 
Russia, (3) Austria-Hungary, and (4) France, and their 
rank is the order named. Nearly every nation grows 
some. 

260. Preparation of the land, seed, and seeding. — 
Very light and very hea\'y soils are to be avoided because 
of poor water-holding capacity and firmness, respectively. 
With other soils, a good supply of organic matter is essen- 
tial to maintain good physical condition, which aids 
materially in holding moisture, in maintaining fertility, 
and in promoting easy penetration of roots. Plowing 
may be from ten to sixteen inches deep according to power 
and implements. In some cases sub-soiling is practiced 
to break hardpans or to loosen compact sub-soils. Deep 



246 



The Principles of Agronomy 



fall-plowing mellows the seed-bed and permits winter and 
spring rainfall to penetrate deeply. Two or three double- 
diskings in the spring will firm the seed-bed and conserve 




Fig. 69. — Sugar-beets require a large amount of hand labor. 

moisture. Factories furnish the seed and, in many cases, 
plant it by contract. The seed has been bred and selected 
for six or seven years to insure high sugar content. If a 



Root Crops 247 

person keeps in mind that percentage of sugar is a variable 
character and that it has been raised from 6 to 16 per cent 
and as high as 25, he will appreciate that without constant 
selection low percentages would result in a few years. 

Seed costs about fifteen cents a pound in America and 
is sown at the rate of ten to twenty pounds an acre, usually 
in April or May, though earlier in some localities and later 
in others. Planting is commonly done with a four-row 
seed drill and a team. From one to three inches is the 
usual depth of planting — slightly less than for small- 
grains — in rows from sixteen to thirty inches apart. 

261. Treatment during growth. — As soon as the rows 
show plainly, the beets are cultivated with a four-row 
cultivator, which follows the rows of the planter. Weeds 
between the rows are removed and the soil is mulched. 
The beets are blocked every six to ten inches by means of 
short hoes. The blocks are thinned by hand to one 
beet in a place. Four or five sprouts come from one seed 
or boll. This and the thick planting to insure good 
stands make thinning necessary. For a time, government 
experts expected to develop seed with single-germs, but 
the experiment was not entirely successful. 

Whenever the soil needs it, further cultivation is given 
the crop. Two or three hand-hoeings remove weeds and 
loosen soil in the row around the plants. Toward the 
end of June or in early July in most irrigated districts, 
furrows are made and five to thirty inches of water are 
applied in from one to four applications. Rather 
thorough soakings seem to be beneficial, as the cultiva- 
tion that follows lessens evaporation, and the greater 
length of time between allows the w^ater to distribute 
itself evenly in the soil. Water-logging must not, how- 
ever, be permitted, since this causes short or branched beets, 
as does compact soil. Not many cultivations can be 



248 The Principles of Agronomy 

given after irrigation, as the leaves soon become so large 
as to be injured. Some farmers count on harrowing six 
or seven times early in the season. 

262. Diseases. — Cultivation necessary for beets 
should be so intensive as to keep weeds well under control. 
The constant selection of beets has prevented diseases 
from causing widespread losses. Heart-rot, leaf-spot, 
and a bacterial disease, however, injure the crop materially 
in some sections. Both disease and insect injury increase 
with the age of the sugar industry and with the presence 
of other plants in the Chenopodium group, including white 
pigweed, Russian thistle, and white tumbleweed. 

Heart-rot and blight {Phonia hetcp), a distinctive 
disease of beets, is the worst hindrance to sugar-beet 
production in Germany, Austria-Hungary, and France. 
It has recently entered this country. Generally in 
August, the inner leaves and then outer ones blacken ; 
both die leaving the bare beet crown. The disease passes 
down into the concentric rings and produces rot, some- 
times almost ruining the crop. The destruction of all 
plant remnants from infested areas prevents spread, 
and treatment of seed with Bordeaux mixture prevents 
propagation of the disease in new crops. 

Leaf-spot (Cercospora beticola) appears on the leaves as 
brown spots with reddish-purple borders which spread 
until the entire leaves become dry. The crown sends out 
new leaves at the expense of the root. The best precau- 
tion, some think, is to spray young plants with Bordeaux 
mixture. 

Beet leaves are also attacked by a bacterial disease 
about which little is known. The disease makes its way 
into the roots reducing yield and percentage of sugar. 
Rotation and care in irrigation are the methods of control 
advocated. 



Root Crops 249 

A chlorotic condition which causes the leaves to turn 
white has appeared in various sections of the West. Up 
to the present time it is not well understood. It is 
thought to be a physiological condition. In general, 
rotation and selection will diminish the injury it causes. 

263. Insects. — Leaf-miners, leafhoppers, beet army- 
worms, beet flea-beetles, webworms, wireworms, cutworms, 
and white grubs injure beets considerably in various 
localities. 

The leaf -miner maggot (Pegomyia vicina) eats under 
the epidermis of the leaves mining out crooked grooves. 
Hand-picking is the only remedy ; deep plowing and 
thorough harrowing lessen the injury the next season. 

Beet leafhoppers (Eutettix tenella), which are very 
small, attack the leaves causing them to curl when it 
is dry and warm and the plants are not shaded. Much 
damage is done in some states by " curly top," as it is 
called. 

Sugar-beet webworm (Loxostege sticticalis) caterpillars 
do damage to beets in July, August, and September by 
eating the leaves. Spraying with arsenicals and deep 
fall-plowing help to control it. The destruction of white 
pigweeds {Cheno podium), closely related to beets and on 
which the beet insects live, is especially important in 
controlling all such insects. 

Caterpillars of the beet army-worm (Laphi/gmo r.vigua) 
eat the leaves. Spraying with arsenicals kills many of 
them. Cutworms, wireworms, and white grubs increase 
in sod which ought to be avoided for beets the first j^'ear 
after plowing. Flea-beetles do considerable damage, 
but no control method known is satisfactory. 

264. Harvesting, marketing, and storage. — Men em- 
ployed by factories sample beets for sugar content and 
purity, telling the farmers when they may harvest. The 



250 The Principles of Agronomy 

beets are loosened and raised from their position by some 
sort of digger or puller, and then topped by hand. 

The crown of the beet as far as it is green, that is, at 
lowest leaf scar, is removed. Leaves are either left on 
the ground or hauled off to feed cattle, while the beets 
are usually hauled directly to the factory, or they are 
loaded on cars by arrangements which dump the load 
from platforms. In rush seasons, however, many beets 
are piled in fields or yards and covered with tops to pre- 
vent frequent freezing and thawing. Freezing seems to 
do no injury unless thawing follows. At the factory, 
the beets are stored in long bins left open to the weather. 
The beets grown for sugar are weighed and the sugar 
company pays the farmer either a flat rate — so much a 
ton — or according to sugar content and purity, — that 
is, on a sliding scale. 

265. Use and value. — The most important use of 
sugar-beets is in the manufacture of sugar, though they 
have considerable feed value. The tops are valuable 
and are often pastured on the ground because they con- 
tain most of the mineral elements of fertility. The 
pulp, a by-product from the sugar industry, is a valuable 
stock-feed, being highly succulent. Beet-sugar manu- 
facturing can never become a farm operation because it 
requires much expensive machinery and many compli- 
cated operations. 

Beet-culture has a decided value on the farm aside from 
the cash returns. The deep plowing, the intensive cul- 
ture, and the fertilization necessary in successful pro- 
duction of . beets improve farming methods materially 
and increase yields of other crops. Weeds are also 
controlled and business methods introduced into agri- 
culture. The farmer, the soil, and the sugar company 
are mutually benefited in most cases. 



Root Crops 251 

266. Manufacture of sugar. — When the factory is 
ready to use the beets in a bin, the end is opened and a 
section of the floor in the bottom of the V-shaped bin 
removed. The beets tumble into a stream of water which 
carries them to rotating paddles or brushes, where they 
are washed and scrubbed. An elevator carries them to a 
weighing hopper, after which they are sliced into cossettes 
and steamed under pressure to dissolve out the sugar. 
The juice, or gar, is mixed with lime to precipitate impuri- 
ties, whereas the pulp is run outside into vats or silos for 
stock-feeding. Carbon dioxide, which is now run into 
the juice, unites with the lime rendering it insoluble and 
causing it to settle and carry to the bottom much of the 
dark, impure substances. Filters remove the small lime 
particles. Lime and carbon dioxide are again added. 
After filtering, sulfur-dioxid gas is passed through the juice 
to remove dissolved lime. Surplus water is boiled off, and 
the juice goes to crystallizing pans for further concentra- 
tion. Before going to the centrifugals, which are steel cyl- 
inders with perforated linings, the sirup is mixed. In the 
rapidly-whirling centrifugals, the liquid is forced through 
the small holes of the lining and the crystals are scraped 
off and dried by a current of warm air. The liquid which 
has not undergone crystallization is saved and again 
concentrated for two more yields of sugar, small ones, of 
course. Sacking is the last process before marketing. 

MANGEL-WURZELS 

267. Description. — Mangel-wurzels, or mangolds, as 
they are variously called, differ from sugar-beets, in that 
they are usually much larger, weighing from four to six 
pounds. Generally they grow partly out of the ground, 
and are very irregular in shape, being largest some dis- 



252 The Principles of Agronomy 

tance below the crown ; they are reddish in color, with 
yellowish or pinkish flesh; and they contain approxi- 
mately 12 per cent dry matter, about half of which is 
sugar, whereas sugar beets are about 20 per cent solid, 
four-fifths of which is sugar. Beef cattle and hogs do 
well on this crop. Dairy cows can use them as a part 
ration, but they demand more solids, especially protein, 
than the succulent mangel can supply. 

268. Use. — The mangel is the chief root crop used 
for feeding in the United States, although in England 
turnips and rutabagas rank first. The value of the mangel 
is in its succulence. Corn silage is displacing it to some 
extent, though in northern United States and Canada 
roots deserve more consideration. One disadvantage of 
roots is that for one ton of dry matter from eight to ten 
tons of water must be handled. The food value of the 
dry matter is high, however, because it is both palatable 
and digestible. Great quantities cannot be consumed 
on account of the excess of water. 

269. Culture. — The land should be prepared as it is 
for sugar-beets. Seeding is done with one-row drills, 
with four-row drills, or by hand on small areas. They 
are planted at the rate of six to fifteen pounds to the acre 
and at a depth of one to two inches. Planting is usually 
done in April or May. The small plants grow slowly 
and it requires care in the first cultivation to prevent 
covering up the rows. Mangels require the same atten- 
tion as sugar-beets in regard to thinning, except that they 
are left farther apart. As to cultivation and irrigation, 
the same methods apply. 

When frost kills the outer leaves, thereby stopping 
growth, mangels are ready to harvest. They are some- 
times pulled by hand or by plowing a furrow close to the 
row. Beet diggers are also used to loosen the roots. 



Root Crops 253 

Mangels in baked soils are especially hard to dig. Yields 
vary from ten to forty tons under favorable conditions. 
About thirty tons may be expected under irrigation. 

After the tops are removed, the roots should be stored 
in a well-ventilated cellar where a temperature just above 
freezing can be maintained. High temperatures are to 
be avoided, particularly, to prevent heating, which is 
dangerous because of the high moisture content. 

TURNIPS AND RUTABAGAS 

270. Description. — Turnips (Brassica rapa) and ru- 
tabagas (Brassica campestris) belong to the mustard 
family (Cruciferse), which include cabbage, kohlrabi, 
and rape in addition to several garden vegetables such as 
radish and cauliflower. Turnips are much smaller than 
rutabagas. They have a much more regular shape ; 
and white rather than yellowish or orange flesh. They 
have a much shorter growing season, and since they are 
more watery they are a less valuable feed. They have 
rough foliage attached to a short, flat crown, while ru- 
tabaga leaves are borne on a neck, become smooth, and 
take on a bluish color. The rutabaga is long and ir- 
regular. Both have a distinct outer layer that peels 
free from the flesh. The root-systems of both are com- 
paratively small. 

271. Culture. — K fine seed-bed is required on account 
of the root-system. Sandy soils seem best, and a moist, 
cool climate is essential to best development. The seeds 
are single-germed and, on this account, require much less 
thinning than do the mangels or sugar-beets. The rows 
should be about as far apart as beets and should be 
thinned to six or eight inches apart in the row. Turnips 
may be planted for winter use as late as July, as a catch- 



254 The Principles of Agronomy 

crop after another crop is removed, or between rows of corn. 
Two or three pounds of seed to the acre are used ; rutabagas 
should be sown twice as thick and usually planted in 
May or early June. Planting ought to be just deep enough 
to place the seed in warm, moist earth. Cultivation, 
.irrigation, harvesting, and storage are the same as for 
mangels save that turnips must be used in early winter. 

272. Value. — In England turnips and rutabagas form 
part of the regular farm rotation, and take the same 
place for stock-feed that mangels do in Germany. They 
are grown in Canada ; in the United States, their culture 
is not extensive. Turnips are used also for human food. 

As feed, rutabagas rank high, enabling the farmer to 
greatly reduce grain rations. Five to fifteen tons of 
turnips and ten to twenty tons of rutabagas are good 
acre-yields. Rutabagas are valuable for beef cattle, 
hogs, and sheep. Because they keep well into spring, 
they serve well for this purpose, particularly where silos 
are not used. They are easy to feed, since only slicing 
is necessary, and this saving of time gives them consider- 
able additional value. Turnips are used for sheep and 
hog pasture. They pull up easily and the use of leaves 
as well as roots is possible. 

CARROTS (Daucns carota) 

273. Description. — The root of carrots may be taper- 
ing,' cylindrical, or short and thick ; they may be white, 
yellow, orange, or reddish in color. An outer layer 
breaks away from an irregular interior that is more watery 
and more palatable. A medium-sized root-system spreads 
outward ; the leaves are finely divided ; white flowers 
are borne the second year in dense flat umbels ; the seeds 
are cup-shaped. 



Root Crops 255 

274. Culture and use. — Loose, sandy soils, in which 
well-rotted farm manure is incorporated, make a warm, 
mellow seed-bed. Seed, at the rate of four to six pounds 
to the acre, is sown as soon as the ground is in good condi- 
tion. Since it is small, the seed requires shallow planting. 
Rows should be about thirty inches apart to permit use 
of cultivators ; the carrots should stand from two to 
four inches apart. If thicker, they should be thinned. 
Irrigation, cultivation, harvesting, and storage are the 
same as for mangels or rutabagas. 

The garden crop is used principally for household pur- 
poses. For forage, larger areas should be grown. When 
used for forage, carrots furnish succulence and are es- 
pecially desirable for horses. 

SUPPLEMENTARY READING 

The Sugar Beet, Ware. 

Field Crops, Wilson and Warburton, pp. 412-422, 451-463. 

Field Crop Production, G. Livingston, pp. 323-336. 

Forage and Fiber Crops in America, T. F. Hunt, pp. 275-303. 

Forage Crops, E. B. Voorhees, pp. 275-291. 

Southern Field Crops, J. F. Duggar, pp. 425-456. 

Cyclopedia of American Agriculture, Vol. II, pp. 539-550, 588-595, 

613-623. 
U. S. D. A. Yearbook for 1904, pp. 341-352. 
Principles of Irrigation Practice, J. A. Widtsoe, pp. 286-298. 
The Commercial Production of Sugar Beet Seed in Utah, F. S. 

Harris, Utah Bui. No. 136. 
American Irrigation Farming, W. H. Olin, pp. 205-228. 
U. S. D. A. Farmers' Bulletins : 
No. 52. Sugar-beet. 

392. Irrigation of Sugar Beets. 

548. Storing and Marketing Sweet Potatoes. 

567. Sugar-Beet Growing under Irrigation. 

568. Sugar-Beet Growing under Humid Conditions. 
615. Leaf Spot, a Disease of the Sugar-beet. 



CHAPTER XXI 
ALFALFA (Medicago sativa) 

Permanent agriculture must be diversified. Not only 
must there be a variety of crops in rotation, but livestock- 
raising must accompany crop production. Horses are 
necessary as beasts of burden ; cattle, sheep, and hogs 
are valuable as milk- or meat-producers. Good hay is 
an important factor in the successful production of live- 
stock. In this alfalfa is unexcelled. In regions that 
have poor shipping facilities, cattle-raising is important. 
Pasturage and hay are essential on both ranch and farm. 
In supplementing the native pastures of the West when 
range lands could not be used in winter or when they pro- 
duced little feed, alfalfa has been of inestimable value. 
In fact, it made possible pioneer settlement in the West. 
An early start, heavy yields of delicious forage, long life, 
and adaptability to arid climates and arid soils promoted 
its spread. So marked has been the effect of all these 
influences that 95 per cent of the alfalfa crop of the 
United States is produced west of the Mississippi. 
Methods of handling the alfalfa crop are shown in 
Figs. 70 to 72. 

275. Name and origin. — Of thirty or forty names by 
which alfalfa is, or has been, known in various parts of 
the world " alfalfa " and " lucern " are most widely used. 
" Alfalfa " seems to be gaining rapidly in popularity, 
largely on account of the adoption of that name in treatises 

256 



Alfalfa 



257 



and in schools. It is Arabic and means best fodder; 
" lucern " is a Spanish-French word taken perhaps from 
tlie name of the town Lucerne in Switzerland. A few of the 
other names are Mexican clover, lifcern clover, perennial 
clover, Spanish trefoil, purple medick, cultivated medi- 
cago, medicago medica, isfist, alfasafat, and monthly clover. 
From the earliest time, alfalfa has been used as forage. 
The Egyptians grew it ; Xerxes carried it from Persia 




Fig. 70. — Mowing alfalf;i 



into Greece about 490 B.C., sowing it at his various en- 
campments to feed his cavalry horses ; it went to Rome ; 
from there to France, and Spain ; Arabs carried it to 
Algeria ; finally, it reached Mexico and spread widely 
across parts of the Americas. In 1853, some settlers 
going to California by way of Cape Horn carried seed 
from Chile to San Francisco. It extended rapidly over 
California and eastward, reaching the Great Plains about 



258 The Principles of Agronomy 

fifteen years ago. Practically every state now grows It 
to some extent. Altliough alfalfa had been introduced 
into southern California from Mexico, and into New 
York from Europe nearly a century before the Chile 
introduction, there was no widespread cultivation. Per- 
haps the favorable conditions that gave the crop a good 
start were necessary to bring its true value to the atten- 
tion of farmer and ranchman. 

276. Relationships. — Alfalfa belongs to the Legumi- 
nosse, in which are thousands of species, among which 
are peas, beans, clover, vetches, locust trees, lupines, 
sweet peas, and the little astragalus common on sage- 
brush lands of the mountain states. In the genus Medi- 
cago, about fifty species are found. 

The legume family is easily distinguished by pea- 
shaped flowers, by pods that break open along both 
sutures, by the compound leaves, and by the tiny enlarge- 
ment on the roots called nodules, or tubercles. In these 
live bacteria which feed upon the plant taking free nitro- 
gen from the air, and assisting greatly in the maintenance 
of soil fertility. In the valleys and on the hills of the 
West, there are fifty or more species of native legumes 
which have probably had much to do with the great 
fertility of virgin lands. 

277. Roots. — Young alfalfa plants send down pro- 
portionately long tap-roots bearing fine branching roots. 
The first stem is single, and lacks tlie crown that develops 
with age. The plant is decidedly perennial livjng from 
four to fifty or sixty years depending on the favorableness 
of the field. The roots continue to grow in well-drained 
soils as long as the plant lives. This results in immense 
root-systems. Roots fifteen to twenty feet in length are 
common ; thirty to forty feet is occasionally reached ; a 
cave in the gravel delta at Logan, Utah, exposed a root 



Alfalfa 259 

fifty-six feet long, while Coburn ^ reports that roots pene- 
trated the roof of a tunnel one hundred and twenty-nine 
feet below the surface of an alfalfa field. Water-tables 
limit depth because roots will not penetrate more than 
six or eight inches into a soil devoid of air. 

Though they are nearly always single tap-roots, three 
or four large roots sometimes displace the single one. 
About half an inch is the usual diameter below the crown. 
The thickness gradually diminishes until the roots are al- 
most hair-like. These fine roots that do the feeding form 
a network in the soil, but they do not form sod because 
they are not stoloniferous. Hence, if all roots are broken, 
the plant dies, since there are no buds except on the crown. 
The fine roots bear, scattered in various places, small 
nodules which are either separate masses or enlarge- 
ments of the roots, and which vary in size from a small 
pin-head to that of a pea. These may be found by 
carefully digging into the root-system of almost any 
alfalfa plant. Some plants, however, bear only a few. 

278. Stems and leaves. — When the stems are har- 
vested for hay, new shoots come out from the thickened 
crown near the surface of the ground. As more and more 
crops are cut, the crowns increase in size until some are 
six inches across, becoming divided into two or three 
distinct parts. Some make the land rough by standing 
four or five inches above the surface. If a harrow splits 
the crown without cutting the roots, separate plants may 
form. 

In spring, young stems develop as soon as the ground 
is warm. These grow steadily until blossoms appear, 
when they stop increasing in size in order to develop 
seed. At this time, the stem may vary from six to sixty 
inches in length and from one-sixteenth to one-fourth 
1 The Book of Alfalfa, p. 6. 



260 The Principles of Agronomy 

of an inch in diameter; twenty-four to thirty inches in 
height and one-eighth of an inch in thickness are usual. 
The stems are usually green, but they are sometimes 
marked with red ; they are hollow with white pith in 
the center; they branch frequently in the axils of leaves 
which are arranged alternately. In general, first-crop 
stems, containing more fibrous material, are much coarser 
than those of succeeding crops. A longer period of 
growth is used by the first crop, in most cases, than by 
later crops. 

Pinnately-compound leaves of three leaflets grow out 
from the main stem and branch first on one side and then 
on the other. Three leaves usually arise from one axis, 
with a middle one much larger than the two side ones ; 
bracts indicate the presence of still other rudimentary 
leaves. The central vein of the compound leaf may, at 
any time, develop into branched stems, or simply divide 
to form the midrib of the leaflets, which are oval-shaped, 
and slightly saw-toothed at the outer end. The midrib 
sends out parallel side veins which show on both surfaces, 
the upper of which is a much darker green and the lower 
slightly hairy. 

279. Flowers and seed. — At blossoming time, each 
branch and the main stem bear at least one cluster of 
pea-shaped flowers that are purple in common alfalfa, 
though some varieties bear yellow and others greenish 
flowers. The calyx is five-parted, compound at the base 
and sharply pointed at the single tips. Separate petals, 
nine stamens in a bundle, one alone, and a compound 
ovary that develops into a pod, form the other parts of 
the flower. Growing pods are distinctly curled, making 
from one to four distinct curves and bearing from one to 
a dozen seed. As maturity approaches, the pods take 
on a dark brown color and the seeds become yellowish, 



Alfalfa 261 

greenish-yellow, or brown. Though alfalfa seed is nat- 
urally kidney-shaped, a large percentage of it is angular 
in various ways, on account of the seeds touching each 
other as they grow. Peas are flattened on opposite sides 
due to lack of room ; but curling in the pod exerts pres- 
sure on the corners, rather than on the sides or ends. 
Failure to mature properly leaves some shrunken seeds; 
others are brown with tough seed-coats. These are 
usually slow to germinate or may even lack the power to 
do so. The seeds are usually about one-sixteenth of an 
inch in length and half that in width and thickness. 

280. Varieties. — In adjacent parts of Asia, Africa, 
and Europe a number of varieties of alfalfa grow wild. 
In cultivation, however, only two distinct kinds find use. 
One is erect, blue- or purple-flowered, and familiar; the 
other yellow-flowered, not well-known, rather creeping of 
stem and stoloniferous, a quality absent in the common 
alfalfa. The second, Siberian, has its chief value in 
crossing with the ordinary plant to give resistant strains. 

A number of strains have been taken from regions in 
which they have been grown for a time long enough to 
become adapted to climate, soil, culture, and use of that 
section. These strains are: (1) "common," (2) 
Turkestan, (3) Arabian, (4) Peruvian, (5) variegated, 
and (0) Grimm. Half a century on the dry-farm has 
given rise to the so-called dry-land alfalfa, which probably 
differs but slightly from the common strain. None of 
these are of special importance save Grimm, which resists 
winter-killing to a remarkable degree. Variegated, a 
cross with Siberian, has variously colored flowers. 

Since, in general, adaptation to a locality determines 
the value of a lot of seed, these cultivated varieties have 
little value. Perhaps we may learn enough about them 
to establish certain strains for particular conditions. As 



262 The Principles of Agronomy 

yet, 95 per cent of our crop continues to be " common " 
alfalfa. 

281. Distribution and adaptation. — Western United 
States, Argentina, Chile, Peru, southern Europe, North 
Africa, South Africa, Australia, and western central Asia 
produce alfalfa extensively. All these sections are semi- 
arid, with hot, dry summers and winters either not rigor- 
ous or else snow-covered. The greatest production by 
states in the United States is as follows: (1) Kansas, (2) 
Nebraska, (3) Colorado, (4) California, (5) Idaho, (6) 
Utah, (7) Montana, (8) Oklahoma, (9) Wyoming, and 
(10) New Mexico. 

A deep, fertile, well-drained soil permits the greatest 
development of the crop, especially when lime is present 
in liberal quantities, as it is likely to be where no leaching 
has occurred. The deep-feeding roots can then supply 
food and moisture abundantly. The right kind of bacteria 
must also be present, since in their absence the young 
plants grow only a few inches high and then die. Some 
soil from an old field scattered over the new patch in- 
oculates it if the necessary bacteria are lacking in the 
new seed-bed. Porous sub-soils are desirable for root 
expansion ; the plants tolerate some gravel. 

Water-logging seriously hinders development of the 
plant by preventing aeration and by causing alkali 
accumulation at the surface. Young plants suffer quickly 
from salt concentrations ; but when older, a corky crown 
enables the plant to resist girdling. Adaptability of the 
crop to either extensive or intensive culture strengthens 
its position as one of the principal crops in the West. 
Alfalfa responds readily to manuring, irrigation, and 
cultivation by increased returns ; it also produces much 
forage on dry-farms. Then, too, it yields best when 
grown only five or six years on one piece of ground, but 



Alfalfa 263 

will continue to produce haj^ for ten, fifteen, or even 
twenty years when conditions are favorable. That such 
a crop is widespread is natural, particularly since it is 
most palatable and nutritious. 

282. Preparation of the land and seeding. — Fall- 
plowing fines the seed-bed and allows rainfall to enter 
the soil freely ; both of these are important for planting. 
Small seed cannot get a hold unless food and moisture 
are at hand. Liberal applications of well-rotted farmyard 
manure warm the soil and increase the available water 
and plant-food. After such preparation, spring-planting 
should give good stands. If deep cultivation is practiced 
the roots penetrate more easily. Lime is necessary on 
acid soils. 

Since fall-planting gives as good results as spring- 
planting, farmers often plant then to save time in the 
spring and to get a larger harvest next season. Li this 
case, the previous crop must come off the land generally 
by August in order to make possible the ready prepara- 
tion of a fine, moist, porous, yet firm seed-bed. August 
or even July seeding permits the plants to establish them- 
selves before winter sets in. When spring planted, 
alfalfa should begin growth as soon as the land is warm. 

One to five pounds of seed to an acre have given, full 
stands, though from ten to twenty are more satisfactory. 
From twenty to thirty pounds are required for successful 
stands in humid regions or on soils in poor condition. 
Drills are almost universally used. Nurse crops of 
barley, oats, or wheat may, or may not, be desirable. 
They are necessary only on very hard or very loose soils. 
In Algeria row cultivation pays, but in American hax-fields 
it is not used, except in small plats planted for seed. 

283. Treatment during growth. — Some farmers har- 
row with spike-tooth, spring-tooth, or disk harrows in 



264 The Princij>les of Agronomy 

spring or fall. Insects, disease, or weeds may necessitate 
special attention. Light applications of farm manure 
pay on some, and irrigation on all soils in arid sections. 

Irrigation water up to about forty inches brings in- 
creased returns. From one to ten applications are made 
either by flooding or in shallow furrows which aid in leading 
the water over difficult patches or in covering large areas 
with small streams. Over-irrigation menaces some dis- 
tricts, since flooding for more than one day at a time may 
" drown " the plants and permit frost to do considerable 
injury. Fall, early spring, and winter irrigation are all 
important in regions of scarce water and mild winters. 
Conservation of rainfall is a fundamental economy in 
all dry regions. 

284. Harvesting. — Under normal conditions, the best 
time to cut the crop for hay is in early bloom. Rakes 
may follow the mower almost immediately — directly on 
dry-farms and well-drained land. Irrigated alfalfa cures 
best if piled in small cocks within a few hours of cut- 
ting — the same day if possible. In this way farmers 
can save the leaves on the stems, which makes the hay 
more valuable than swath-cured hay. In rainy weather, 
moreover, hay suffers more in the swath than in com- 
pact piles. 

When bull-rakes are used, hay cures in heavy windrows 
and is pushed to the stack without being loaded on wagons. 
Various kinds of forks and nets and several types of der- 
ricks unload the wagons, which are loaded by hand almost 
entirely, though loaders are used in some sections. On 
dry-farms, a ton to the acre pays ; one and one-half to 
two and one-half tons are frequent. Four or five tons 
for the season is a good return under irrigation, though 
six to eight are harvested from an acre under favorable 
conditions. 



Alfalfa 



265 



285. Storage. — Most hay is kept out-of-doors. 
Stacks with upright sides with middles high and built 
solid from the ground up, topped with rounding slopes 




Fig. 71. — A convenient device for stacking hay. 



that leave no " shoulders " for storms to enter keep well, 
while irregular squatty piles lose heavily. Good stacking 



266 



The Principles of Agronomy 



requires much skill. Sheds are preferable, since it is 
not necessary to stack carefully under cover. 

Most hay is fed on the farm or marketed loose in the 
vicinity. When shipments are made, the hay is com- 
pressed into bales weighing from 50 to 150 pounds. Baled 
and loose hay are usuall}' weighed on wagons for market, 
although stacks are often measured. Inaccuracy in 




Fiu. 72. — Hay should be fed on the farm. 



measuring due to variation in shape, regularity, and 
density cause this to be unsatisfactory in many instances. 
286. Use and value. — In palatability, digestibility, 
nutrition, and healthfulness, alfalfa hay leads. Some 
horsemen prefer timothy because alfalfa is laxative for 
driving horses. A part of the preference for timothy is, 
however, due to custom. Work animals need only moder- 
ate grain ration when alfalfa is fed because of the high 
protein content. It excels as roughage for dairy cows, 



Alfalfa 267 

beef cattle, and sheep. As silage it has not been success- 
ful because of difficulty in compacting. 

Ground hay is used in mixed feeds as alfalfa meal. 
It wastes less and compounds in rations more readily, 
but otherwise it has no advantage over hay. 

Alfalfa pasturing is widely practiced in spite of the 
danger of bloat to cattle and sheep. Dew-covered leaves 
eaten by hungry stock may prove injurious. Horses 
and hogs may feed on alfalfa pastures any time. If 
cattle are left continuously on the feed night and day, 
danger diminishes but it never disappears. Wisdom is 
necessary in pasturing cattle and sheep on the growing 
crop. After haying, nearly all fields are grazed over 
indiscriminately. Withered stands need cause no alarm. 
Extremely close pasturing weakens the alfalfa, for it is 
not stoloniferous and forms no true sod. 

287. Mixtures are generally detrimental in that they 
lessen the yield. On account of maturing at a different 
time, they also hurt the quality of the hay by introducing 
coarse, woody stems or undesirable beards. Orchard- 
grass, timothy, Kentucky blue-grass, and Bermuda- 
grass are mixed with alfalfa purposely or creep in nat- 
urally, but they are unsatisfactory and are considered 
weeds. Squirrel-tail, locally known as foxtail (Hordeum 
jubatum), dodder, sweet clover, yellow trefoil, June-grass 
quack-grass, and crab-grass all cause trouble. Thorough 
harrowing and occasional plowing are the remedies for 
almost all weeds in alfalfa. 

288. Enemies. — Besides weeds, root-rot, stem-blight, 
leaf-spot, and several minor diseases do varying damage 
to the crop. Rotation and cultivation largely control 
them. Stem-blight, which seriously attacks the stems 
of the first crop only, can be controlled by cutting as 
soon as the disease appears. 



268 



The Principles of Agronomy 



No widespread insect does constant damage. Grass- 
hoppers may be disregarded if fall-plowing and clean 
farming are practiced. Hibernations are thus destroyed. 




Fig. 73. — Dodder on alfalfa plants. 



Swarms from waste lands occasionally cause trouble. 
Various traps for catching them have been devised. 
The chalcis fly has recently done much seed injury in 



Alfalfa 269 

the West. It enters the ovary at bloom, lives inside the 
seed, and bores out by a small clear-cut hole in the pod 
just before maturity. Thrips also injure the seed-crop 
at blooming time. 

In 1905, the alfalfa leaf-weevil (Phytonomus posticus) 
appeared in Utah and has since spread rather widely 
over the state and into southern Idaho and south- 
western Wyoming. Small green larvae feed on the 
growing buds, usually of the first crop, thus delaying 
the second crop and causing the third cutting to be 
small or lacking. If the first crop is cut as soon as 
the larvse appear in numbers sufficient to do marked 
injury, and if the land is thoroughly spring-toothed 
followed by a weighted brush-drag after the surface 
has dried, the weevil nearly disappears on that patch 
for the rest of the season. Besides the good which 
cultivation does in destroying weeds and insects, it con- 
serves moisture by forming a mulch. Contrary to public 
opinion, the seed cannot carry the insect into new dis- 
tricts. 

289. Seed production is confined almost entirely to 
dry regions because constant moisture encourages the 
growth of new shoots which lessen seed bearing. Half 
the seed produced is on irrigated lands where water can 
be withheld. Dry-farms produce most of the rest. 
Second-crop alfalfa bears most of the seed. Even in 
arid regions, seed-producing sections are isolated \^alleys 
or areas. Row cultivation has given the best yields of 
seed on some arid farms. 

Seed alfalfa generally ought to be thinly sown. 
Bumble bees aid in cross pollination but much self- 
fertilization takes place. 

Mowers or binders cut the seed stand and threshers 
are used to separate the straw from the seed. The straw 



270 The Principles of Agronomy 

and chaff are used for feed. From one to twenty bushels 
weighing from sixty to seventy pounds are harvested 
from an acre. 

SUPPLEMENTARY READING 

The Book of Alfalfa, F. D. Coburn. 
Alfalfa in America, J. E. Wing. 
Forage Plants, C. V. Piper, pp. 305-360. 
Field Crop Production, G. Livingston, pp. 278-293. 
Forage and Fiber Crops in America, T. F. Hunt, pp. 170-199. 
Alfalfa in the Southwest, G. F. Freeman, Ariz. Bui. No. 73. 
Cyclopedia of American Agriculture, Vol. II, pp. 192-197. 
American Irrigation Farming, W. H. Olin, pp. 141-169. 
U. S. D. A. Farmers' Bulletins : 
No. 194. Alfalfa Seed. 

339. Alfalfa. 

373. Irrigation of Alfalfa. 

495. Alfalfa Seed Production. 

637. The Grasshopper Problem and Alfalfa Culture. 



CHAPTER XXII 

THE CLOVERS AND OTHER LEGUMES 

Alfalfa is the important forage crop west of the 
Mississippi. Red clover is similarly important north of 
the Ohio and east of the Mississippi, save that it has 
timothy for a teammate in furnishing forage. What 
alfalfa is to the West, and red clover to the North, cow- 
peas are to the South : the important legume forage. 
The other legumes yield seed or hay, and all are able to 
fix atmospheric nitrogen. They also have high-feeding 
value as a result of high protein. 

RED CLOVER {TrifoHum pratense) 

Red clover is the most important leguminous crop grown 
in the United States. i\.s a forage, it and timothy com- 
pete for first place leaving alfalfa third. The acreage 
of red clover diminished about 40 per cent from 1899 to 
1909 due to the increasing difficulty of getting good stands 
on old farms. Some attribute this to " clover sickness," 
an abnormal condition little understood but partly 
remedied by long rotations. 

Romans and Greeks never saw red clover. Not until 
the thirteenth century is there record of its use as forage. 
It was near the end of the eighteenth century before 
Europe cultivated it extensively. Early colonists carried 
it to Massachusetts, where mention was made of it as a 
crop in 1750. 

271 



272 The Principles of Agronomy 

290. Description. — The root-system confines itself 
largely within the plowed soil sending a few roots down 
four to six feet and occasionally eight. A small crown 
sends up hairy, much-branched stems bearing many pal- 
mately compound leaves which are generally patterned 
with white on the upper surface. Dense, globular flower- 
heads rise from the end of all branches. Fifty to one 
hundred and fifty small blossoms varying from pale pink 
to red comprise these heads. The whole plant presents 
a bushy appearance every part of which is covered with 
fine hair. 

Cross-pollination seems necessary to seed production. 
Bees aid greatly in carrying pollen from plant to plant. 
When mature, the seeds, which are in most cases heart- 
shaped, vary from yellow to deep purple in color. From 
twenty to one hundred develop in one head. 

Ordinary red clover is about a foot in height with 
hollow stems ; a variety known as mammoth clover is 
large and has solid stems. Mammoth clover blooms at 
the same time as timothy and is better, therefore, to use 
in a timothy mixture than red clover, which blooms two 
weeks earlier. A much larger second crop is sent up by 
red clover. Like alfalfa, red clover has many strains 
named from the sections that grow them. In general 
the strains are much alike, with each best in its own home. 

291. Distribution and adaptation. — Red clover is 
widely cultivated in Europe, Chile, and New Zealand as 
well as in the United States. In all northeastern states, 
it ranks with timothy as the leading forage. In acreage, 
the states stand in the following order: (1) New York, 
(2) Iowa, (3) Missouri, (4) Michigan, (5) Wisconsin, (6) 
Pennsylvania, (7) Illinois, (8) Ohio, (9) Indiana, and (10) 
IMinnesota, — every large state north of the Ohio and 
Missouri rivers and east of the arid section. This area 



The Clovers and Other Legumes 273 

of production is entirely within that part of the humid 
section which is damp without rigorous winters. Just 
northward, in the Canadian provinces of Ottawa and 
Ontario, where similar climatic conditions exist, an im- 
mense area is planted to this crop. 

The soils on which it grows vary widely. About all 
that is required in this respect is that they be moist and 
well-drained. Fertile cla\'s produce the best yields ; 
sand or gravelly soils that hold little water, the poorest. 
As both water-logging and drouth are injurious, red clover 
has no wide adaptation either on dry-farms or under 
irrigation, though it is profitable in many high valleys of 
the West. High temperatures prevent extensive culture 
of it in the South. Northern and western European 
countries, where it is grown extensively, have a cool, 
moist climate. 

292. Culture. — About eight pounds of seed to an acre 
is planted any time from early spring to earl}' fall, with 
or without nurse crops. A fine, firm seed-bed is essen- 
tial. Lime and farmyard manure pay best as fertilizers. 
Fall-planted clover yields a hay crop the first season, 
but when it is spring planted, little hay grows that season, 
though the next two crops net good returns. The second 
cutting may produce seed instead of hay. Two to three 
tons of hay and from one to six bushels of seed is a satis- 
factory return. 

Farmers cut, cure, and handle the hay and seed much 
as Westerners do alfalfa, but with greater difficulty on 
account of wet weather in the particular section to which 
it is adapted. Cutting at full bloom gives the best hay. 

293. Use and value. — Red clover hay ranks high in 
the East. It is superior to grass, but not so good as 
alfalfa. As silage, it is good if cut fine and packed tightly. 
It makes a good soiling crop and fair pasturage, though 



274 The Principles of Agronomy 

it will bloat sheep and cattle. In rotations it fixes atmos- 
pheric nitrogen in the soil, which benefits the next crop 
materially. Because of lasting only two years, it enters 
naturally into practically every rotation where it can be 
grown. Disease-resistant strains and better-planned 
rotations seem to be much needed, at least where " clover 
sickness " prevails. 

OTHER CLOVERS 

294. Alsike clover ( Trifolium hybridum) . — Alsike is 
much like red clover save that it is smooth, more cold- 
resistant, has light pink flowers and brown seed, and can 
endure water-logging with much less injury. It succeeds 
where " clover sickness " and wet lands kill red clover. 

295. White clover (Trifolivni, repent). — White clover 
is common in lawns and pastures. Because of its creeping 
habit of growth, haying machinery cannot gather it 
readily. Acre-yields are small when harvested for hay, 
since only the leaves and flower stalks can be gathered. A 
variety known as Ladina clover is grown for ha^ in 
northern Italy. 

Since it has a creeping habit, its stems hug the ground 
rather closely. Roots grow out from these branches 
giving the plant a new start. A nearly fibrous root-system 
aids in forming sod, which helps to withstand tramping in 
pastures and lawns. Wherever cool weather prevails 
and plenty of moisture is present, white clover thrives. It 
grows from Canada to Mexico where these conditions 
exist, and does well in shady places. 

296. Sweet clover {Melilotus alba) is a rank-growing 
biennial, having an abundance of small white flowers 
and coarse stems which become woody after blooming. 
Cumarin gives the plant a bitter taste and a characteristic 



The Clovers arid Other Legumes 275 

odor that repel stock. Being a legume, it is rich in nitro- 
gen. The plant is deep-rooted, resists drouth, but can 
also tolerate wet soils. It likewise withstands both heat 
and cold to a marked degree. It grows on any soil, 
thriving on roadsides, ditch banks, and on irrigated land 
not carefully cultivated. In some sections, it covers the 
mountain sides. 

Stock feed on it in waste places. Coarse woody stems 
and bitter taste lessen its palatability. If cut, however, 
before blooming, the stems cure in such a way that they 
are soft and the bitterness is less intense. Stock like the 
hay. Its wonderful adaptability and good yields recom- 
mend its cultivation in sections, where, for some reason 
neither alfalfa nor red clover is profitable. 

297. Crimson clover (Trifolium incarnatum), much 
grown in the middle Atlantic and Southern States for 
a green cover-crop, bears a flaming crimson flower, from 
whence its name. This clover is a winter annual in the 
South and a spring annual in the North, where it is occa- 
sionally found. As a hay crop, it lacks some of the valu- 
able properties of other clovers. It bears many hairs 
which, in the intestines of horses, occasionally form balls 
causing death to the animal. Danger of bloat also 
accompanies its use as a pasture. Despite these un- 
desirable qualities, it is widely used as feed ; for green 
manure and rotation it is valuable. 

Hungarian clover, Mexican clover, berseem, shaftal 
or Persian clover, yellow trefoil, and the bur clovers fur- 
nish some forage in small districts. 

FIELD-PEAS (Pisum avvense) 

298. Description and adaptation. — The field-pea, often 
known as the Canada field-pea, resembles the garden pea 



276 The PrincijAes of Agronomy 

save that it is more thrifty and has longer stems, larger 
leaves, violet instead of white flowers, and smoother and 
slightly smaller seed. In depth, the root-system seldom 
exceeds three feet, while the stems vary from one to ten 
feet in length. The stems, which are hollow, stand up- 
right in the early part of the season but soon flatten down 
on account of the length of the vines. On the whole, 
the plant is smooth and rather succulent, covering the 
ground almost completely in good growth, or clmibing 
plant stalks and frames by means of tendrils at the termi- 
nal division of pinnately-branched leaves. Being an annual, 
it grows and matures rapidly in 75 to 110 days. Earli- 
ness, color of flower, shape of pods, variation in seed, and 
length of vine factor in differentiating about a hundred 
varieties, some of which are favorites in one place and some 
in another. All of them, however, do best in cool, moist 
climates and on heavy loam soils. On account of being 
adapted to the same conditions as oats, field-peas grow in 
the same sections, often in the same fields mixed with 
them. Southern Canada and the Northern States 
produce most of the crop, though many high valleys in 
the West yield fairly well. Ontario, Michigan, and 
Wisconsin, in order, lead in acreages. Excessive heat, 
which peas cannot withstand, prevents their cultivation 
south of Maryland. 

299. Sowing. — The abundance of food in the large 
seed permits fairly deep sowing — from one to four inches, 
even on a coarse seed-bed. Fall-plowing in the North 
renders possible early sowing, since the pea has consider- 
able frost resistance and may be seeded as soon as heavy 
frosts are over and as soon as the condition of the land 
permits. 

Farmers commonly plant from one and one-half to 
three and one-half bushels an acre when peas are planted 



The Clovers and Other Legumes 277 

alone. If sown with oats, as they often are for hay, 
usually from one to two bushels of peas and from one- 
half to one and one-half bushels of oats are sown. On 
irrigated land, about two bushels of peas and one bushel 
of oats are used. Both are drilled at the same time, but 
some persons favor separate planting or even broadcast- 
ing. 

300. Culture and harvesting. — Since the peas are 
sensitive to mechanical contact and not grown in rows, 
little cultivation is given after they come up. Three to 
six inches of irrigation water, where used, may be applied 
at intervals of from one to several weeks, depending on 
the physical composition and condition of the soil and on 
the needs of the crop. The shading and heavy lodging 
of the crop render over-irrigation more undesirable on 
clays or clay loams not underlaid with subsoil than in 
sandy or gravelly areas. Peas grown alone are har- 
vested for hay by cutting with a mower before they begin 
to ripen, and they are cured like alfalfa. For hay, oat- 
and-pea mixtures are cut when the oats are in soft dough, 
and they are handled as other hay ; for seed, mowers with 
attachments for piling the vines are used, or a man lifts 
the swath aside so that the horses and machine will not 
shell out the peas. "Grain threshers, with teeth removed 
from the concaves to prevent breaking the seed, separate 
pods and vines from the peas. 

301. Use. — Pea hay, if properly cured, is palatable and 
nutritious. Dairy cows, beef cattle, sheep, and hogs 
relish it and make rapid growth on it because of the abun- 
dant protein which it contains. Horses use it advanta- 
geously. When it is mixed with oats or beardless barley, 
all classes of livestock do well on it. The necessity of 
annual sowing prevents its " more general use for hay. 
Then, too, the green vines are good for soiling, while 



278 The Principles of Agronomy 

hogs and other animals pasture it to advantage. The 
extreme palatability of the green vines makes it valuable 
in a mixed ration. Refuse vines and pods from factories 
that can garden peas are valuable feed if preserved in 
stacks or silos. Fruit-growers and others who want green 
manure find peas good in spite of the fact that shallow 
rooting lessens their sub-soiling value. 

BEANS (Phaseolus species) (Fig. 74) 

302. Description. — Beans belong to the same family 
as peas, and though there are several genera most of them 
belong to the genus Phaseolus. The plants have a shal- 
low semi-tap root-system, rather erect stems, broad, 
hairy leaves, and long tendrils. The flowers vary through 
whites, yellows, and blues ; the pods are generally long ; 
the seeds may be practically any color or shape. In size 
they vary from one-eighth to one and one-half inches 
in length. Nearly all varieties are smooth. 

Unlike peas, beans cannot withstand frost. They 
resemble corn in that a slight frost not only retards but 
stops growth. On this account, they are limited to sec- 
tions that have four months free from frost, that is, from 
about the middle of May to the middle of September. 
Michigan and New York produce 60 per cent of the beans 
grown in the United States. California, Florida, and Wis- 
consin are also heavy growers. Cool, moist climates 
and rich, loamy soils promote the greatest development, 
but under irrigation they may resist fairly hot, dry 
weather. Loose, warm, well-drained soils rich in lime 
may be displaced by poorer ones, though at cost of high 
yield. 

303. Culture. — Fall-plowing prepares the warm, mel- 
low seed-bed that is best for beans. Fine manure also 



The Clovers and Other Legumes 



279 



helps. Late planting permits spring-plowing, which 
ought not, however, to be delayed until just before plant- 
ing as is often the case, since too much moisture evaporates 
and the soil does not become sufficiently firm for good 




Fig. 74. — A good crop of field beans. 



germination. From a peck to a bushel an acre is planted 
by hand, by planter, or by grain drill with the width 
regulated by stopping some of the holes. Planters can 
drop the beans in hills or in drill-rows. 

As soon as the rows show well, cultivation should begin 



280 The Principles of Agronomy 

in order to loosen the soil and kill weeds, and it should 
continue at intervals until the vines become so large that 
they would catch on the cultivator. Cultivation should 
be given after every application of irrigation water, which 
may be used in moderate quantities from one to five 
or six times. 

As soon as the beans are mature enough to prevent 
shrinkage, they may be cut and stacked to avoid loss from 
shelling, which they do at complete maturity. Two- 
row bean cutters make harvesting easy, while bean thresh- 
ers simplify threshing. An ordinary grain thresher, 
slowed down to avoid splitting the beans, does satisfac- 
tory work. Beans pay fairly well but are not widely 
grown. They seem to have gained gradually in the 
last few years, having been introduced into many dis- 
tricts in which they were not formerly grown. Nearly 
all experiment stations in the West give favorable reports 
for some variety, but this is not surprising, because there 
are so many varieties that they are adaptable to widely 
different conditions. 

304. Use. — Beans sell well on the market, dried or 
canned. They have considerable feeding value for stock 
as grain when ground and mixed with other feeds ; they 
seem to have a laxative effect when fed alone. Some- 
times the green plants are cured for hay or they may be 
pastured. To whatever use the plants are put after har- 
vest, they always fix some nitrogen in the soil during 
growth. 

COWPEAS (Vigna Sinensis and V. Cat. jarg) (Fig. 75.) 

305. Description. — Cowpeas are not peas at all, but 
beans, differing from the garden bean in that they have 
long, wrinkled pods, generally long, trailing vines, and 



The Clovers and Other Legumes 



281 



large leaves. The stems are grooved ; the flowers white, 
violet, or yellow; the seeds small, wrinkled or smooth, 
and white, yellow, green, or brown. A branching tap 




Fig. 75. — Cowpeas in Missouri. 



root-system that fills the surface soil penetrates three or 
more feet into the soil. 

Warm and not over-damp climates favor cowpeas ; 
hence they do well through the eastern part of the United 
States south of the Ohio River. Well-drained soils pro- 
mote rapid growth. Since these conditions prevail rather 
generally in the South, the cowpea thrives in this sec- 
tion where given an opportunity. In the last few years, 



282 The Principles of Agronomy 

the crop has grown much in importance. What alfalfa 
is to the West, and what red clover is to the North, cow- 
peas are to the South : a leguminous forage crop of high 
feeding, pasture, and rotation value. Cotton lands 
need a rotation badly and such a one as will support 
livestock. In this, cowpeas excel, for they furnish large 
yields, good pasture, and abundant organic matter whether 
fed or used as green manure. The maintenance of greater 
numbers of livestock, so necessary for the South, will 
depend largely on this crop. 

306. Culture. — Well- worked seed-beds, warm and 
not water-logged, are essential. From two pecks to three 
bushels of seed an acre are broadcasted or drilled ; planted 
alone, or mixed with sorghum, corn, Johnson-grass, millet, 
or soybeans. Since its chief value is for forage it is cut 
green and cured in the field or on racks as the weather 
permits. Ripened seed is hand-picked or threshed from 
the vines. 

Cowpea hay seems equal if not superior to red clover, 
and is nearly as nutritious as alfalfa for cattle, sheep, 
and hogs. As pasture, it has considerable value, espe- 
cially when planted in corn fields late in the season to be 
" hogged-off." Note Fig. 79. 

SOYBEANS {8oja max) 

307. Description. — Soybeans resemble other beans 
in general, but they are more erect, more woody, and more 
hairy. The root-system consists of a well-developed 
tap-root with few side branches. Blossoms vary in 
color from white to purple; the pods are usually short, 
flat, and tawny ; most seed is flat, smooth, and oily. 
In height, the plant varies from six inches to several 
feet, but two to three feet is most common. At this 
height, the fields present a compact appearance on ac- 



The Clovers and Other Legumes 283 

count of prolific branching. When the seed ripens, the 
entire plant dies, since it is an annual. 

Both the climatic and soil requirements for soybeans 
approximate those for corn rather closely, except that 
frosts are not nearly so injurious. Warm, moderately 
moist growing-seasons and warm, loose, soils rich in lime 
are best. Like all other legumes, the right kind of bac- 
teria must be in the soil to secure luxuriant growth, 

308. Culture. — Well-prepared seed-beds aid materi- 
ally in early germination. Seed is commonly planted 
during May at the rate of twenty to thirty pounds an 
acre in drilled rows. From two to four inches seems the 
most favorable depth. Shallow cultivation may begin 
as soon as the rows show plainly, and continue until 
the size of the plants prevents the use of horse and culti- 
vator. Weeds injure the crop seriously and must, there- 
fore, be kept out. The plan of irrigation for cowpeas 
is practically the same as that for field beans. 

When used for hay the time to cut is just as pods form. 
The rake ought to follow the mower closely in order to 
prevent the leaves from drying too quickly. Curing 
is best done in the cock, because the stems do not then 
get too hard nor the leaves over-brittle. Cattle, sheep, 
and hogs, for which the crop is best adapted, do not relish 
the stems as they do softer food. jMixtures of corn, 
cowpeas, sorghum, millet, and grass increase the yield, 
but not the quality, which is naturally high. Hogs, 
particularly, do well on soybean pastures. For seed, 
the crop is handled as are field beans. 

MISCELLANEOUS LECxUMES 

309. Vetch {Vicia). — Of the many kinds of vetches, 
common vetch and hairy, or winter, vetch are most fre- 



284 The Principles of Agro7iomy 

qiiently grown for forage. These plants are annuals and 
winter annuals, respectivel}'. The root-systems are 
branching and only moderately deep ; the stems are long 
vines ; the numerous leaves are finely divided ending 
in tendrils. Purple flowers are borne in compact masses 
on a pedicel ; flat, broad pods bear small dark seeds which 
are fairly hard. Hairy vetch is covered with abundant 
velvet-like hairs. 

Common vetch does well in cool, moist climates that 
do not get very cold. Pacific Coast regions are favorable. 
Hairy vetch does well in temperate regions that favor 
soft winter wheats. It seems adapted to these regions 
on account of being fairly drouth-resistant. 

From forty to sixty pounds of seed will sow an acre 
whether drilled or broadcasted. Mixing with oats or 
grass, which help to support the tangled vines, is usually 
recommended for pasture and hay. The method of 
curing vetch hay differs but little from that of alfalfa. 

The hay is fine and palatable, especially for cows and 
sheep. Horses like it less than clover, alfalfa, or peas 
on account of its extreme softness. For soiling and silage 
it is good. Annual planting and mediocre yields make 
it less valuable than alfalfa, for only one full crop can be 
cut. Farmers may grow their own seed, thus reducing 
the expense of planting. 

310. Other legumes. — Peanuts are grown in the 
South for hog pasture and for nuts. Tangier peas, 
ochrus, fenu-greek, lupines, serradella, lespedeza or Japan 
clover, velvet beans, Florida beggar weed, jackbeans, 
mung beans, moth beans, hyacinth beans, guar, sanfoin, 
kudju, bird's-foot trefoil, astragalus, chickpeas, and 
grasspeas are used in various parts of the United States 
and the Old World for hay or pasture. They are all 
legumes and valuable as nitrogen gatherers and for feed, 



The Clovers and Other Legumes 285 

but they are of secondary importance to alfalfa, the 
clovers, peas, beans, and cowpeas. Vetch and soybeans 
seem to be growing in importance and cowpeas are much 
urged for the South. 



SUPPLEMENTARY READING 

Forage Plants, C. V. Piper, pp. 361-570. 
Field Crops, Wilson and Warburton, pp. 355-374, 390-412. 
Field Crop Production, G. Livingston, pp. 253-277, 294-322. 
Forage and Fiber Crops in America, T. F. Hunt, pp. 140-173, 201- 

374. 
Forage Crops, E. B. Voorhees, pp. 167-208, 231-274. 
Cyclopedia of American Agriculture, Vol. H, pp. 206-212, 235-349, 

260-267, 467-469, 510-514, 582-586, 658-660. 
U. S. D. A. Farmers' Bulletins : 
No. 224. Canadian Field Peas. 

237. Lime and Clover, pp. 5-7. 

260. Seed of Red Clover and its Impurities. 

289. Beans. 

318. Cowpeas. 

323. Clover Farming on the Sandy Jack Lands of the North. 

441. Lespedeza or Japan Clover. 

455. Red Clover. 

485. Sweet Clover. 

515. Vetches. 

529. Vetch Growing in the South Atlantic States. 

550. Crimson Clover : Growing the Crop. 

561. Bean Growing in Eastern Washington, Oregon and 
Northern Idaho. 

579. Crimson Clover. 



CHAPTER XXIII 



GRASSES 



To the grass family belongs a host of plants similar 
in structure yet varying so widely in size and usefulness 
as to seem unrelated. Between lawn grass and gigantic, 
tree-like bamboo is a wide gap partly filled with larger 
grasses such as timothy, sorghums, and corn, which reach 




Fig. 70. — The effective use of li^ht machinery in huiuiliuii the hay crop. 



great size in some climates. Thousands of species belong 
to this family. Among them are many of our most 
useful plants. In fact, the grasses are probably our most 
valuable plants, since with them are classed all the cereal 

286 



Grasses 



287 



crops, most of the forage and pasture plants except a 
few legumes, and most of the range and prairie plants. 
In addition, some species serve man as lawns, as orna- 
mental plants, as weaving material, and as packing for 
furniture and other breakable commodities. 

Some writers class with the grasses all hay and pasture 
plants, — clover and alfalfa as well as members of the 




I'll.. I 7. — A covcreil haystack in .the Iminid secti 



Gramineae, or grass family. Only the true grasses will 
be treated here. Among the most useful of these are 
the grain, the hay, and the pasture crops. Not all grasses 
are useful, since some are our worst weeds. The hay crops 
are fundamental to the nation's prosperity. Methods of 
handling these crops are well shown in Figs. 76 to 78. 

A fibrous root-system with or without rootstocks ; 
stems composed of nodes and internodes which are either 
hollow or filled with a porous pith save at the nodes; 
leaves clasping the culm for a distance above the node 



288 The Principles of Agronomy 

from which they spring and terminate in narrow, parallel- 
veined blades; a branched head bearing seed with a 
closely-borne covering : these are the important structural 
characteristics of the grass family. The forage grasses are 
timothy, redtop, orchard-grass, brome-grass, blue-grass, 
Johnson-grass, oat-grasses, rye-grasses, fescues, wheat- 




FiG. 78. — A good supply of forage well stacked. 

grasses, meadow-foxtail, and a few others. The first five 
mentioned are much more important than the others. 

TIMOTHY {PMewn pratense) 

Timothy originated in the Old World where a number 
of wild species are found. The name probably came from 
Timothy Hansen, who introduced the crop into Mary- 
land from New England. 

311. Description. — Timothy bears a slender, spike- 
like panicle from one to twelve inches in length on a 
slender culm one to six feet in height. From three to 
eight leaves branch off from the upright stem. As the 
roots are not strongly stoloniferous, the plant does not 



Grasses 289 

sod heavily. An enlarged stem known as a corm forms 
a base for the dozen or so culms. As many as two hun- 
dred stems have grown on one plant. 

A patch of timothy shows purple when in bloom ; green 
when headed completely ; and whitish when the seed is 
ripe. During early growth, however, only the leaves 
show. These bend in graceful curves from a central 
stem. Seed of timothy is small — not over one-fourth 
milluneter in diameter — with a thin, transparent, 
adnate hull. Since germination power is high, good 
stands are easily obtained. The seed loses less in via- 
bility through age than does that of other grasses. Eighty 
per cent of two-year-old seed may be expected to grow. 

312. Adaptation. — Cool, moist climates and clay or 
clay loam soils offer the most favorable opportunities 
for maxhnum yields. Severe drouth kills it almost im- 
mediately ; hot weather, even in humid sections, lessens 
its vigor ; cold is favorable to some extent as indicated 
by the fact that the plant is native in Europe as far north 
as the seventieth parallel. Favorable conditions exist 
in many high valleys in the West, especially where streams 
supply abundant irrigation water. In spite of its fond- 
ness for moisture the plant suffers from water-logging. 
In fact, timothy and red clover are mixed to a great extent 
because the same conditions favor both. In the United 
States the production of timothy ranks as follows ac- 
cording to states: (1) New York, (2) Iowa, (3) Ohio, (4) 
Missouri, (5) Illinois, (6) Pennsylvania, (7) Wisconsin, 
(8) Michigan, (9) Indiana, and (10) Minnesota with 
Ottawa and Ontario in Canada heavy producers. Red 
clover ranks nearly the same as timothy according to 
states. Every state produces some timothy. 

313. Culture. — Fine, moist, firm seed-beds are essen- 
tial in procuring successful stands of timothy — of any 



290 The Principles of Agronomy 

crop having very small seed. Well-decayed organic 
matter increases both moisture and fertility. Fall- 
plowing permits frost to mellow the surface; winter 
storms dampen and firm the seed-beds for spring planting. 

About half the crop of the United States is sown in 
the fall with winter wheat for a nurse crop. In this case 
a grass seed attacliment drops the seed just in front of, 
or just behind, the shoes of the drill. A light harrowing 
covers the seed, though Piper ^ thinks deeper planting 
would be better. The seeds must touch moist soil in 
order to germinate, and should be planted from a half 
inch to one inch in depth depending on the season and 
soil. Seed may also be planted in the fall without a nurse 
crop, and in spring with, or without, a nurse crop. 
Broadcasting both by hand and by means of the wheel- 
barrow seeder is much practiced. Irrespective of the 
method used in planting, the farmer should sow about 
fifteen pounds of seed to the acre. 

In some sections, corn or potato land is prepared by a 
thorough harrowing without previous plowing. In most 
sections, however, fall-plowing, spring-harrowing, and 
drill-sowing give the most satisfactory stands. Fre- 
quent irrigations pay on lands that have good drainage. 

Heavy applications of farmyard manure to the stub- 
ble pay. Where commercial fertilizers are used, nitrog- 
enous manures make most profitable returns. Clover 
mixtures serve this purpose. 

Timothy ought to be cut as soon as the blossoms fall, 
but it does not deteriorate rapidly until the seed reaches 
the soft dough stage. This enables the farmer to utilize 
a later harvesting season than for any other forage crop. 
The hay cures readily, being in many cases hauled on the 
same day that it is cut. In humid sections, tedders, side- 

' Piper, Forage Plants, p. 130. 



Grasses 



291 



delivery rakes, and loaders are widely used ; in the West, 
it is handled largely as alfalfa. Derricks are used to 
build stacks and tracks to fill barns. The first crop bears 
most seed. Grain binders commonly harvest the seed 
crop, which is threshed in an ordinary separator with 
special sieves. 

314. Use and value. — The most important use of 
timothy is for hay, since the pastures yield but little feed 
and the sod weakens under tramping. As a silage or a 
soiling crop it is little used. Though the standard hay 
crop of America, its intrinsic feed value is less than that 
of the clovers or alfalfa on account of its lacking the high 

Table 3. Acreage and Yields of Forage Crops in the 
United States. (From Piper.) 



Crop 



Acre- 
yields 



Aches 



Tons 



Per Cent 



Timothy (alone) . 
Red clover (alone) 
Timothy and 

(mixed) ^ . . 
Timothy (total) . . 
Red clover (total) . 
Alfalfa .... 
Cereals for hay . . 
Other tame grasses 
Sorghums . . . 

Millet 

Cowpeas .... 
Canada peas . . . 
Kentucky blue-grass 
Brome-grass . . . 
All other tame grasses 
Wild grasses . . . 



clover 



1.22 
1.29 



1.22 
1.29 
2.52 
1.24 
.99 
1.05 
1.38 
1.00 
1.00 
1.00 
1.00 
1.00 
1.07 



14,675,000 



19,536,000 

24,457,584 

12,274,454 

4,704,146 

4,324,878 

4,218,9.57 

2,078,242 

1,117,769 

1,100,000 

2.50,000 

100,000 

1,000,000 

600,000 

17,186,522 



30,3.59,698 

15,532,602 

11,859,292 

5,367,292 

4,166,772 

3,118,863 

1,546,5.33 

1,100,000 

250,000 

800,000 

100,000 

600,000 

18,383,574 



31.2 

15.9 

12.2 

5.5 

4.3 

3.2 

1.6 

1.1 

.3 

.8 

.1 

.6 

18.9 



^ Taken as half clover and half timothy when grown in mixture. 



292 The Principles of Agronomy 

protein content of legumes. Common grasses vary little 
in food value or digestibility. Palatability, ease of cur- 
ing, prolific seed production, healthful ness, and yield- 
ing power determine what grass is most profitable to grow. 
Timothy excels other grasses in these qualities. Market 
demands influence price ; the prejudice of farmers and 
stockmen also plays a part, often not an insignificant 
one. Timothy has an advantage also in that it is the 
standard market hay, and that many stockmen prefer 
it to clover and alfalfa, in spite of the fact that it surpasses 
them only for feeding driving horses. 

315. Enemies. — Bill-bugs and joint-worms cause some 
insect injury; a rust and a smut infest the plant. The 
greatest harm, however, comes from leaving meadows 
sown too long without rotation. This causes the stand 
to be so thin as to reduce yields materially. 

REDTOP {Agrostis alba) 

316. Description. — Redtop is so called from the dis- 
tinctly reddish appearance of a field of it in bloom. It 
is more long-lived than timothy, its stems are more slender 
but tougher, its leaves finer, its sod more compact but 
more shallow, and its panicle much more spreading. The 
seeds are small, light, triangular in shape, and generally 
grayish-brown in color. The compact sod is a result of 
niunerous rootstocks, and of decumbent stems sending 
out roots from the nodes. 

317. Adaptation. — As redtop withstands water-log- 
ging to a marked degree, it replaces timothy on very 
wet land, sometimes growing in sloughs or bottom-lands 
in which water stands part of the year. It resists as 
much cold as timothy and more heat. It grows in all 
parts of the United States and as far north as Alaska. 



Grasses 293 

It has an extremely wide adaptability in regard to soils, 
provided they are wet. Strange to say, when once es- 
tablished it resists considerable drouth. 

318. Culture. — Pastures nearly always contain red- 
top in mixtures, but seldom does it form fields grown by 
itself. Since seed varies much in viability, from two to 
fifty pounds are planted, from two to ten pounds being 
common in mixtures. Much of it on wet land is started 
by broadcasting the seed, often without any cultivation, 
whatever. For hay, it is handled as timothy. In irri- 
gated pastures, it occupies the wettest places. 

319. Value and use. — As feed, it is much less palat- 
able than timothy or blue-grass, but because of being 
able to endure water-logging and tramping it is valuable. 
It grows well on soils too wet or too acid for blue-grass 
and timothy, and grows wild on many of the boggy range 
lands, where it supplements the native grasses. In lawns 
it forms a fairly smooth sod, but becomes coarse unless 
kept well cut. 

On the market it is considered an adulterant of timo- 
thy, the price of which it lessens. As the yield is fair, 
no particular objection can be made to it. 

KENTUCKY BLUE-GRASS (Pou pratensis) 

320. Description. — Kentucky blue-grass is marked 
by its smooth, firm sod, fine stems, and blue-colored 
leaves, which end without a distinct point. The panicle 
is loose and turns whitish at maturity. There are sev- 
eral blue-grasses, but the only other common one is 
Canada blue-grass {Poa compressa), which may be told 
by its sparsity of leaves, tough stem, and compressed 
panicle. It yields less than Kentucky blue-grass, being 
considered a weed on that account. 



294 The Principles of Agronomy 

321. Adaptation. — Apparently no degree of cold 
kills this grass, though it loses vigor in hot summers 
even when abundant water is supplied. Naturally 
adapted to temperate regions, it thrives in this zone 
wherever sufficient moisture falls on well-drained soils 
that are rich in lime. It can endure neither acidity nor 
water-logging. Nearly all of the seed grown in the United 
States is produced on a few hundred square miles near 
Lexington, Kentucky, which is in the heart of the Blue- 
grass Region. 

322. Culture. — Because of the low vitality of the 
seed, heavy seeding is required for good stands. If 
sown alone, forty pounds may be needed. Usually 
the farmer sows smaller quantities in mixtures. In many 
cases blue-grass, due to persistent spreading by means of 
rootstocks, will drive out other crops, leaving nearly a 
straight stand. Fine, moist soils, well mixed with hvunus, 
are best. The seed is most often broadcasted and har- 
rowed. Better stands may be had on lawns by covering 
them with straw, or by shading in another way. Nurse 
crops may or may not help in field culture. This de- 
pends on soil and climatic conditions. 

323. Use and value. — Blue-grass yields little forage 
that may be gathered for hay. As a pasture plant, it is 
king in America, though meadow-foxtail is most popular 
in England. Mixed with white clover, Kentucky blue- 
grass forms the best pastures in this country and also 
the best lawns in the North and West. Bermuda-grass, 
however, supplants it in the South. 

Its popularity for pasture is not without reason. 
Though yields are small, it is so aggressive that bare 
spots are soon filled. It gains rather than loses under 
heavy pasturing, if it gets sufficient moisture. All ani- 
mals are fond of the grass when it is green. When dry it 



Grasses 295 

is much less desirable, however. In palatability, fresh 
blue-grass excels all others, with the possible exception 
of smooth brome-grass. On account of its aggressiveness, 
it is a bad weed in clover and alfalfa fields. The legumes 
yield much more heavily, and suffer when blue-grass 
creeps in, since it eventually crowds them out, unless 
frequent harrowings or occasional rotations follow, 

ORCHARD-GRASS (Doctylis glomerato) 

324. Description. — Orchard-grass is a deep-rooted, 
rather rank-growing, bunchy, yet leafy grass. The shape 
of the panicle suggests a cock's foot, by which name it is 
known in England. Bunching is due to vigorous roots 
devoid of stolons. Tufts sometimes two feet across cause 
decidedly rough surface, bare in many places. These 
tufts are strongly netted by means of miiny tough, fibrous 
roots. Undoubtedly, the plant roots three or four feet 
deep in favorable soil, 

325. Adaptation. — Heat injures orchard-grass less 
than it does timothy or blue-grass, but cold hurts it much 
more seriously. The natural place for its cultivation 
is just south of the timothy belt. It is to be regretted 
that timothy has gained such a hold that other useful 
grasses, such as orchard-grass, oat-grass, and brome-grass, 
were not tried in regions too warm or too dry for the 
greatest development of timothy. Porous, well-drained, 
fertile soils permit orchard-grass to make best growth. 
The plant uses considerable moisture to advantage, 
though, when necessary, it can, with the help of deep 
roots, endure rather severe drouths. As shade does not 
injure the crop to a great extent, it does well in orchards. 

326. Culture. — Similar care as to preparation of the 
land for sowing, and method of scattering the seed, 



296 T'he Principles of Agronomy 

should be observed in the case of orchard-grass as in that 
of the other grasses. Both spring and fall planting suc- 
ceed. Fall planting should take place early enough to 
permit some growth before winter ; spring planting gives 
best results when the ground has become warm but is 
still damp. 

When sown alone for hay, from twenty-five to forty 
pounds of seed are used. More commonly, from four 
to ten pounds are planted in mixtures. Patches grown 
for seed require a stand only half as thick as hayfields. 

Orchard-grass makes the best hay when cut in early 
bloom, as the stems become woody very rapidly, thus 
decreasing palatability. Because this grass matures 
several days before most other grasses, mixtures are 
usually unsatisfactory for hay on account of the varia- 
tion in time of cutting. Harrowing and manuring help 
to keep up yields and to prevent the growth of excessively 
large bunches. Applications of irrigation water up to 
thirty or forty inches pay in the West, though smaller 
quantities yield more in proportion to the water used. 

327. Value and use. — Orchard-grass yields about as 
much hay as timothy and more second growth, which 
consists largely of leaves, making it valuable for fall pas- 
turage. Since it begins growth early, it also affords con- 
siderable spring pasturage. Where severe and continuous 
tramping injures the roots, bare spots appear at intervals. 
Other grasses are needed to keep a good sod in pastures. 

Hay from over-ripe orchard-grass is coarse and woody ; 
unless very carefully cured it lacks the palatability of 
timothy or blue-grass. The shortness of the period 
during which it may be cut and still make good hay is 
a decided drawback. Early maturity, on the other hand, 
aids in keeping down weeds in the crop and permits 
pasturing of the fields. 



Grasses 297 

SMOOTH BROME-GRASS (Bromus inermis) 

328. Description. — There is a large number of brome- 
grasses, most of which are hairy or have barbed seed. 
Chess, the wheat pest of the East, is Bromus secalinus; 
the June-grass or cheat-grass of the West, which has 
recently become a pest in alfalfa fields and on ranges, 
is Bromus tectorum. Among all these but one is really 
valuable. Smooth brome-grass is neither hairy nor 
barbed. On the other hand, an abundance of broad, 
smooth, succulent leaves marks its early growth. Round 
stems and broad leaves distinguish it from other common 
grasses before the culms head out. 

When fully grown, B. inermis is likely to be three to 
four feet in height bearing a strikingly great number of 
leaves, many culms, and an open-panicled head often 
distinctly golden in color. This imparts considerable 
beauty to good stands. To support this growth a strongly 
stoloniferous root-system dives six or seven feet into po- 
rous soils. 

329. Adaptation. — Deep rooting enables brome-grass 
to resist dry weather remarkably well. It seems to be 
one of the most successful grasses under low rainfall. 
Although frost injures the plant but little, too much heat 
prevents good growth in the South. Grown for ages in 
semi-arid Russia, this grass promises well in the northern 
part of the West, especially on the Great Plains. Arid 
soils are the best for root development, in that they are 
generally deep, porous, and fertile. The greatest growths 
are found on loams and clay loams. 

330. Culture. — If practiced in arid regions, fall- 
plowing and the summer fallow will store moisture for 
spring planting of brome-grass. In many localities, fall 
seeding on well-prepared seed-beds, treated as if for fall 



298 The Principles of Agronomy 

wheat, is, however, probably more satisfactory. From 
ten to twenty pounds an acre are planted for hay and from 
four to ten for pasture. Because the seed clogs the drill 
holes, farmers usually broadcast and cross harrow it. 

When it is once established, severe harrowing improves 
its growth by preventing the fields from becoming sod- 
bound. Applications of barnyard manure help to main- 
tain yields on fields five or six years old. Moderate 
quantities of irrigation water are beneficial. By care- 
ful handling, the crop ought to succeed in some localities 
on the dry-farm. 

331. Value and use. — For hay, the grass is cut just 
after full bloom and cured as is alfalfa. The abundance 
of green leaves makes curing more difficult than is the 
case with other grasses. The arid regions in which it is 
largely grown overcome this objection in part by offering 
bright haying weather. Brome-grass will cure where 
alfalfa does. The high percentage of leaves to stems 
gives the forage an inviting look and a desirable softness. 
The grass is probably more nutritious and a higher yielder 
than other common grasses. Its great palatability causes 
stock to relish it highly. 

Pastures of brome-grass wear well, furnish much feed, 
and grow early as well as late. Some investigations sug- 
gest that it be mixed with alfalfa for pasture. Where 
alfalfa is used for hay and thrives, this should not be 
done, as grasses yield less and the value of alfalfa is low- 
ered. 

In spite of the many good qualities of brome-grass, it 
may prove undesirable. Not enough is known about it 
to make it advisable to plant great areas with impunity. 
However, it promises so well as to deserve a trial. Farm- 
ers should try the grass in small areas, or get advice from 
their Experiment Station, or from growers in their neigh- 



Grasses 299 

borhood before sowing extensive fields. Brome-grass 
varies widely. Keyser of Colorado found 121 variations. 
Wisdom in selecting the correct variety for hay or pas- 
ture on irrigated or dry-farms may lead to unqualified 
success with this new crop. 

. OTHER GRASSES 

332. Tall meadow oat-grass {Arrhenatherum elatius) is 
an erect-growing perennial bunch grass that thrives 
under the same conditions as orchard-grass. It with- 
stands more heat, more drouth, but less frost than timothy. 

It does not count for much in American agriculture 
at present, but ranks high in France and other parts of 
Europe, where it is grown for hay. When heavily pas- 
tured, it weakens rapidly because of inability to fill unoc- 
cupied soil, due to its lack of rootstocks. Its long life 
increases its value to some extent. Perhaps, it may find 
some regions too warm for timothy and brome-grass, 
too gravelly and too dry for other common grasses where 
farmers need such a crop-plant. 

Oat-grass is sovv^n in either fall or spring without a 
nurse crop because it cannot endure shade to any marked 
degree. Heavy seeding is necessary on account of the 
low viability of seed. Eighty pounds are frequently 
used when the crop is grown alone. More often about 
twenty pounds are sown in mixtures with orchard-grass, 
with alsike clover, or with both. 

A bitter taste lessens the palatability considerably. 
If cutting is delayed till after bloom, the culms get 
woody. A yield slightly higher than that of the ordinary 
grasses partly counterbalances its poor quality. 

333. Bermuda-grass (Cynodon Dactylon) is valuable in 
lawn and pasture in the South. It is an exceedingly 



300 The Principles of Agronomy 

strong sod-former often serving effectively in preventing 
erosion on unprotected soils. Wherever moisture abounds 
and regular frosts do not occur, it resists tramping and 
grows continuously save in early spring. Lawns in the 
South are almost universally of this grass, which keeps 
green in hot summer but is brown in winter and early spring. 

Little seed is produced ordinarily. New stands are 
started by planting small pieces of sod in furrows on a 
firm, moist seed-bed. These should be two to three feet 
apart each way for fields and one foot for lawns. Heavy 
disking opens up the sod causing a more vigorous growth 
when fields have become sod-bound. 

When used for hay, each cutting is small, but with a 
fertile soil and a warm, moist climate, several growths 
make a high total yield. In many cases, however, suc- 
cessful hay crops are not produced. In feeding value, 
it is very similar to timothy. Because of its aggressive 
underground stems, it is a bad weed in many fields. 
To eradicate it, men who have studied the grass recom- 
mend shallow plowing just preceding dry, hot weather 
or frost. Smothering it with cowpeas or some other rank- 
growing crop is sometimes successful. 

334. Johnson-grass {Holciis halepensis) is a coarse, 
broad-leaved grass closely related to sorghum. Produc- 
ing both seed and large rootstocks abundantly, it spreads 
rapidly by means of irrigation ditches in warm sections 
such as the South, Arizona, and southern California. 
Johnson-grass succeeds anywhere in the cotton belt. 
In fact, it not only succeeds but usurps fields unless it is 
carefully guarded against. Difficulty of eradication has 
caused farmers to regard it as a noxious weed, in spite of 
the fact that it is probably the best hay grass in the South, 
frequently yielding as much as five tons a year. If 
cut young, the quality of hay is fair, but pastures are 



Grasses 301 

only medium because the succulent rootstocks weaken 
when it is grazed closely. Stock have occasionally been 
fatally poisoned as they are sometimes by sorghum. 

Freezing of the soil below six inches in depth kills the 
plant. Where growth is vigorous, eradication is best 
accomplished by plowing before frost or drouth and then 
planting the soil to a crop that is to be intensely culti- 
vated, such as cotton, or to a crop that will smother the 
pest, such as oats and vetch. 

335. Miscellaneous grasses. — Two rye-grasses, sev- 
eral fescues, meadow-grass, and slender wheat-grass are 
cultivated in various small districts or throughout broad 
regions in scattered patches. Western wheat-grass and 
slender wheat-grass grow in bunches throughout the moun- 
tain region. Many sedges (Carex sp.) and rushes Juncus 
sp.) are erroneously regarded as grasses. In sloughs 
and wet bottom-lands, they furnish much low-grade hay 
and rough pasture. On salt lands, salt-grass {Distichlis 
spicata) makes a small growth of medium quality. These 
last are not cultivated, but are harvested from native 
meadows largely by ranchmen, who wish a coarse rough- 
age to feed cattle over winter. 

SUPPLEMENTARY READING 

Farm Grasses of the United States, W. J. Spillman. 
Meadows and Pastures, J. E. Wing. 
Textbook of Grasses, A. S. Hitchcock. 
Forage Hants, C. V. Piper, pp. -307-348. 
Field Crop Production, G. Livingston, pp. 194-238. 
Forage and Fiber Crops in America, T. F. Hunt, pp. 1-99. 
Farm Grasses of Ohio, C. G. Williams, Ohio Bui. 225. 
Cyclopedia of American Agriculture, Vol. H, pp. 365-377. 
U. S. D. A. Farmers' Bulletins : 

No. 402. Canada Blue Grass. Its Culture and Uses. 

502. Timothy Production on Irrigated Land in the North- 
west. 



CHAPTER XXIV 

PASTURES, MEADOWS, AND SOILING 
SYSTEMS 

The pasturing of livestock on grassy plains and steppes 
was the most primeval form of agriculture. As civiliza- 
tion increased, man left off hunting and took to tending 
flocks and herds. Soon he found it profitable to have an 
understanding with his neighbor as to whose cattle were 
to graze on particular areas. Abraham and Lot divided 
their pasture-lands for this purpose. Later, when crops 
became important, livestock were still necessary. Thus 
to-day, wherever man lives, he has cattle and beasts of 
burden. These get a part of their feed from pastures 
or from unoccupied public lands, called ranges. 

336. Definition. — By the term " pasture " is meant 
any land from which livestock gather feed for themselves, 
as opposed to soiling, which is cutting and feeding the 
green plants, or as opposed to hay-making, which con- 
sists of curing the crop by drying it before feeding. It 
makes no difference whether the areas are man-made 
or whether they are natural, nor does it matter what the 
nature of the plants grown may be, so long as they are 
used for feed. 

337. Kinds of pasture. — If the area is naturally cov- 
ered with pasture crops, or if the land is continuously used 
for the grazing of livestock, the pastures are said to be 
permanent. These permanent pastures are either range 

302 



Pastures, Meadows, and Soiling Systems 303 

land, meadows, or sloughs. A part of the extensive 
prairies east of the Rockies is still a range pasture. 

The meadows and fields renewed occasionally — regu- 
larly or irregularly — are temporary pastures. They 
consist either of fields left sown for a number -of years or 
for one or two seasons. In many sections the stubble 
of grains and forage crops is pastured. These, strictly 
speaking, are not pastures, that is, the primary use is 
not for pasture but for crop harvests. Nevertheless, 
they are of economic importance. 

338. A good pasture should be thoroughly and evenly 
covered with plants that will form sod of such a nature 
as not to be injured by the tramping of animals nor be 
checked in its growth through close cropping. These 
plants ought to be so palatable and fine as to encourage 
the animals to eat sufficient quantities, and so nutritious 
that the quantities eaten will nourish the body and supply 
energy for work, whether it be drawing loads, growing wool, 
or manufacturing milk. The pasture needs to be green 
a considerable part of the year, and to yield much feed. 

339. Importance. — More than one-third of all the 
improved farm land in the United States is in pasture. 
In the West, the range land far exceeds the farm land in 
area. Part of the farm land — perhaps a third or more 
— is in temporary pasture. Much western land is so 
dry that it cannot be classed as grazing land, although 
sheep feed on it. 

Immense droves of sheep and cattle formerly grazed 
throughout the West. The day of the cattle kings is 
passing rapidly where it is not now past, but forest re- 
serves still furnish pasturage for numerous animals. 
The animals, taken from the range lands in the fall, are 
turned into the meadows and stubble fields to pick at 
the ungathered plant parts. In some sections they winter 



304 The Principles of Agronomy 

on meadows supplemented with a partial ration of hay. 
The convenience of a pasture in which to turn animals, 
especially during haying and harvesting, is of consider- 
able value. Much labor is also saved. 

340. Native grass, together with rushes and sedges, 
largely comprises these meadows. The sedges (often 
called broad-leaf), with three-cornered stems and broad, 
bunched leaves, and the rushes (wire-grass and bulrushes), 
with round, hollow, stemlike leaves, grow abundantly 
in the wet valley bottoms and sloughs. These supply 
considerable second-class feed on the wet lands that are 
impregnated with alkali. Salt-grass and related species 
also grow in similar places making finer hay and better feed. 

Wheat-grasses, lupines, wild vetch, and numerous other 
plants occur on the ranges. Sheep get considerable graz- 
ing from sagebrush and shadscale. 

341. Crop-plants. — Kentucky and Canada blue- 
grasses, timothy, redtop, smooth brome-grass, orchard- 
grass, tall meadow fescue, Italian and perennial rye- 
grasses, tall meadow oat-grass, and red, white, and alsike 
clovers are all used in permanent and temporary pastures, 
and some of them for hay. In addition to these, alfalfa, 
the small-grains with and without a mixture of peas, rape, 
corn, and millets are used to varying extents in different 
localities. In general, these yield more palatable and 
more abundant feed than the native grasses. Except 
redtop, they thrive best on well-drained soils that are 
fairly rich in lime. Lime and drainage are especially 
necessary for Kentucky blue-grass, timothy, brome-grass, 
alfalfa, and red clover. Blue-grass and the rye-grasses 
need much moisture. 

342. Mixtures help in many ways : 

(1) They usually insure a continuous growth from 
early spring through summer to late fall. 



Pastures, Meadows, and Soiling Systems 305 

(2) They render the feed more palatable because of 
variety, and more nutritious, when the grasses have 
legumes sown with them. 

(3) They usually increase the yield, as they can be 
made to feed in different soil layers or during different 
seasons of the year. This is more likely to be true when 
deep-rooted and shallows-rooted crops are grown together. 

(4) The legumes aid in keeping up the fertility. 

(5) Deep rooting loosens the sub-soil thus promoting 
drainage and increasing available moisture. 

(6) A plant that establishes itself in one season when 
mixed with one requiring two or more years, yields feed 
until the other can get well started. 

Just what mixture to use is always a question, since no 
set of conditions is exactly like any other. There are all 
variations within a given mixture, according to the land, 
to the animals pastured, and to the fancy of the owner. 

The Utah Experiment Station has found the following 
three mixtures well adapted to the irrigated West : 

For bench lands under irrigation : 

Kentucky blue-grass 12 pounds 

Smooth brome-grass 8 pounds 

Perennial rye-grass 6 pounds 

Orchard-grass 3 pounds 

White clover 2 pounds 

Red clover 2 pounds 

Alfalfa 2 pounds 

For light sandy soils under irrigation : 

Kentucky blue-grass 8 pounds 

Meadow fescue 12 pounds 

Tall meadow oat-grass 5 pounds 

Smooth brome-grass 8 pounds 

White clover 2 pounds 

X 



306 The Principles of Agronomy 

For low, wet lands such as sloughs : 

Perennial rye-grass 8 pounds 

Redtop 10 pounds 

Rhode Island bent-grass 4 pounds 

Meadow fescue 2 pounds 

Alsike clover 5 pounds 

White clover 2 pounds 

A mixture used with success on the good soils of the 
East is as follows : 

Timothy 10 pounds 

Red clover 4 pounds 

Alsike clover 3 pounds 

White clover 2 pounds 

Kentucky blue-grass 3 pounds 

Tall meadow fescue 2 pounds 

Orchard-grass 2 pounds 

For poor land in the humid sections, the following is 
often used because it is cheap : 

Timothy 3 pounds 

Redtop 5 pounds 

Alsike clover 5 pounds 

White clover 2 pounds 

Kentucky blue-grass is the most popular of all single 
pasture plants. The long dry periods encountered in 
dry-farm regions prevent the formation of good pastures. 
Various experiments on dry-farms show that smooth 
brome-grass and rye are successful. Timothy has done 
best on the mountain ranges, with brome-grass second, 
Brome-grass has a deep root-system and forms a sod resist- 
ant to tramping. This, except that it does not sod 
strongly, is likewise true of alfalfa, which is sometimes 



Pastures, Meadows, and Soiling Systems 307 

used for dry-farm pasture, particularly when either the 
first or second crop promises to be too small to pay for 
cutting. Many farmers turn the animals on stubble to 
gather remnants which would dry up and be lost by blow- 
ing away. Pastures on dry-farms seem to be more suit- 
able for horses than for other animals. 

343. For different animals. — One reason why horses 
do best on dry pastures is that they need rather large 
fields which promote exercise. They do not feed so 
close to the ground as to injure the root-crowns of alfalfa. 
They can get on with less water than some other animals, 
but need it regularly. They do not bloat as do cattle and 
sheep. 

Cattle need a more succulent feed, and more water, 
than horses ; therefore, green pastures are more valuable, 
particularly for milch cows. Since cattle eat rapidly, 
they sometimes bloat, especially on alfalfa wet with dew. 

For sheep small pastures used in rotation are recom- 
mended in order to keep down parasites. Fine feed is 
desirable ; resistant sod is preferable, as they eat close 
and injure the roots of such plants as alfalfa, timothy, 
and orchard-grass. They bloat easily on alfalfa and some 
grasses. If there are no willows in the field, there should 
be sheds to provide shade. 

Hogs like coolness and water. They do as well on 
small pastures, since they require little food at one time. 
Shade and water in the feed lot compensate for small 
area ; this, however, does not imply that food should 
be scarce. Hull-less barley and peas, corn and rape, 
corn, rape, barley and vetch, oats and vetch, oats and 
peas, and barley make good crops on which to turn hogs. 
They also dig out root-crops to advantage. 

Poultry do better when they have access to green 
feed. Grains and alfalfa are used most. 



308 The Principles of Agronomy 

344. Condition of pastures. — It is a common prac- 
tice to utilize land not easily handled in the regular 
cropping system for grazing. This land may be too rocky 
to permit the use of plows and other machinery. It may 
be water-logged or covered with water ; covered with 
willows ; rough and uneven ; cut up by sloughs and low 
ridges ; or filled with some native growth such as rushes. 
Sometimes the very extensiveness of a man's ownings 
renders it impossible to farm the land with the equip- 
ment he has. His livestock may roam at will over what- 
ever part of the public domain is unreserved. A number 
of serious faults are here suggested. In addition, too 
many farmers permit bunches to develop and weeds to 
get a hold in a part, or all of the field. Some parts may 
be too dry, even when other parts are covered with water. 
Finally, many pastures are not yielding to their full 
capacity on account of a poor stand of plants. 

345. Improving pastures. — The rocky and very rough 
areas will, for a long time at least, be left in pastures, as 
not much else can be done with them. Removing many 
rocks is rather expensive. 

Draining will much improve meadows that are too wet 
either in the spring or throughout the season. Land that 
is water-logged in the spring is likely to suffer for water 
later in the summer because the water-holding capacity 
is lowered by puddling, and because a shallow root- 
system is produced by excess water. A combination of 
drainage and irrigation will remedy this condition. 

Brush-lands generally need partial or entire clearing 
before they become good pastures. Firing, grubbing, 
and sheep or goat pasturing help to clear brushy districts. 
Rushes and sedges tend to give way slowly to the more 
valuable grasses after lands are drained. Plowing and 
resowing may substitute this slow method. The farms 



Pastures, Meadows, and Soiling Systems 309 

that are yet unimproved will gradually disappear with 
the development of the country, and the permanent 
grazing lands will be made to yield grain and other crops. 

The bunches are rejected forage close to a spiny weed, 
such as a thistle, but usually near a manure dropping 
which seems to taint the grass or drive off the animals by 
its odor. Harrowing two or three times a year with 
brush-drags or spike-tooth harrows, or disking, loosens 
the soil and scatters the manure, making good fertilizer 
from that which in heaps was repellent. The harrow, 
supplemented by a grubbing-hoe, removes the weeds 
that cause cattle to leave grassy bunches. 

Thin stands may be made thicker by harrowing and 
by sowing extra seed. Overstocking causes too close 
grazing, which injures the pasture as well as the animals. 
The remedy is manifestly one of prevention. 

Fertilizers, particularly farm manure, increase the 
yield if they are well scattered. Finally, constant use, 
even when unaccompanied by overstocking, is bad. Al- 
ternating on two or three pastures will prevent this injury. 

346. Overstocking. — The pasture, which requires but 
little attention, is regarded by many as clear profit, 
though the yield is small. The sooner this idea is thrown 
aside, the sooner truly successful pastures will be de- 
veloped. A number of points deserving attention have 
already been indicated. 

Overstocking is putting on the land a greater number of 
animals than the feed can maintain. The animals soon 
go short of the best feed, and under stress of hunger eat 
the coarse, perennial plant parts. Sheep and hogs eat 
root-crowns and occasionally the roots themselves. 

Deforesting and heavy sheep pasturing have practically 
ruined some of the best ranges. In parts of the West, 
cattlemen have come to realize this and they now compel 



310 The Principles of Agronomy 

the sheepmen to keep their flocks away from designated 
districts. Forest reserves handle the situation by limit- 
ing the number of animals that may be pastured on the 
reserve. In excessive hunger during a snowstorm, for 
example, a herd of range cattle ate at the oak brush, 
leaving no branches smaller than an inch in diameter. 

Practically the same thing happens in over-grazed 
meadows. At first the stand gets poor ; then bare spots 
make their appearance ; and, finally, the surface becomes 
tramped, rooted-up, and barren except in spots. Of 
course the animals cannot keep in good condition. The 
greedy owner loses on both the animals and the pasture. 

347. Management. — Manifestly, the remedy for over- 
stocking is to prevent the injury. Proper discretion must 
determine the number of animals that may pasture a 
field, and the time they should feed, continuously. Strong 
sod will bear close grazing longer than will weak. Timo- 
thy, orchard-grass, and clovers, except the white, suffer 
immediately. Blue-grass, redtop, sedges, and rushes 
are rather persistent and will withstand considerable 
close feeding. It is not profitable to pasture too closely, 
however, except in an emergency. 

It is doubtful whether pastures of the less persistent 
grasses should remain longer than a few years without 
being plowed. The plants may weaken, the soil structure 
break down, and parasites accumulate until the old sod 
is a menace. Some of the most successful pastures are 
a part of the farm rotation. In its turn, say every four 
to ten years, the pasture may be moved with advantage 
to the plant, the soil, the animals, and the farmer. 

Horses should not always be pastured in one meadow 
and cattle in another. Feeding habits differ enough to 
be a factor in pasture management. With a large field, 
it is usually better to use only part of it at a time and rotate 



Pastures, Meadows, and Soiling Systems 311 

the animals if they are not to be mingled. Dairy cows 
should not be worried by horses nor be in contact with 
the wallows of hogs. 

A part of the pasture should be allowed to go unused ; 
it needs a rest. This permits the plants to grow up. 
Legumes and other plants that grow at the end of the 
stem demand this more insistently than the grasses, the 
leaves of which have their growing point near the base 
of the leaf-blade. They grow without starting from the 
ground each time as must other plants. Parts of the 
grass will not be eaten down. To encourage a fresh start, 
the mower should be run over these spots at least twice 
a year. Then the coarse stems make better hay when 
cut. In many cases horses and cattle will pick up the 
clipped stems, although they avoid them while standing. 

Sometimes, early in the spring, grass is not as palat- 
able as it is a few weeks later. Waste is often prevented 
by waiting before turning the animals into the field. The 
yield and palatability of young grass increase with age. 

348. Meadows. — In general, meadows for the pro- 
duction of hay demand about the same attention as 
pastures. Drainage of the wet land, irrigation of the 
dry, the use of superior crops, the removal of weeds, the 
reseeding of spots that are killed, and the renewal by 
rotation all deserve intelligent practice. Less attention 
is paid to harrowing and crop mixtures. For hay, plants 
should mature about the same time, while in pastures 
they should mature at different times, except when the 
meadows are used for pastures a part of the year as many 
are. 

The natural meadows, as already indicated, are being 
gradually replaced by cultivated grasses or other hay- 
crops, because these yield more hay of better quality. 
In river- and lake-bottoms, much land is still bearing 



312 The Principles of Agronomy 

salt-grass, sedges, rushes, blue-grass, and redtop, all cut 
for small hay yields. Many of these areas cannot be 
reclaimed on account of the expense in labor and capital, 
and, therefore, will persist as pastures for a long time. 



SOILING 

349. Use. — In sections of the United States that 
have to feed cattle from high-priced land, and where 
labor is cheap, pastures are being partly replaced by soil- 
ing. Animals are not pastured but are fed on green for- 
age hauled to them soon after it is cut and before it has 
lost its moisture. Succulence is especially valuable for 
dairy cows and for stock being raised for beef. 

In Germany, soiling is practiced generally, while in 
Denmark, the animals are tethered in the fields instead 
of being allowed to pasture. In both of these countries 
land is high-priced and labor is cheap. Land must be 
made to produce as much as possible, because extensive 
tracts are not available to the farmers, consequently 
waste about the edges of the fields is decreased in every 
way. Fences are commonly omitted, permitting all the 
land to be cultivated. Since the United States still 
has unused areas that may be pastured, soiling and tether- 
ing are not practiced, except locally. Some of the soiling 
crops are shown in Figs. 79 to 82. 

350. Value. — Disadvantages of soiling are : 

1. Much more labor is required to mow and feed the 
crop in small quantities each day than to pasture or cut 
the entire field at once. 

2. Haying each day is a hindrance to other farm work 
and is inconvenient on that account. 

3. In stormy weather it is very disagreeable to handle 
crops. 



Pastures, Meadows, and Sailing Systems 313 

4. It is difficult to provide a series of crops that will 
supply continuous green feed throughout the summer. 
Among the advantages of soiling the chief ones are : 
1. Greater crop returns are had from an acre than 
from pasture. This comes about by allowing the crops 




Fig. 79. — A good hog pasture of cowpeas and corn. 



to grow until near maturity, by preventing injury to 
plants from tramping, and by avoiding a puddled condi- 
tion of the soil due to animals moving about on it in wet 
weather. 

2. There is less expense for fences necessary to pastures, 
and less waste of land along fence lines that grow weeds. 



314 



The Principles of Agronomy 



3. The feed is more economically used, since there is 
no folding from manure heaps. 

4. The cattle can be kept more comfortable when fed 
green forage than when exposed to the hot sun or to wind 
and storms in open pastures. 







,i?^< --^' 







^ 

>' 






Tfr.* '* 



A-.-«^.*yJ--^ 




Fig. 80. — Sorghums are adapted to hot, dry climates. 

5. Manure can be preserved and applied to the right 
.crop in rotation, thereby conserving fertility. 

6. In consequence, about three times as many cattle 
may be kept on a given area of land. Their gain in flesh 
is greater or their milk flow is kept more even than under 
other systems of feeding. 

The disad\'antages oft'-set the advantages in such a 
way as to cause the utilization of crops for soiling to be an 







^^^ 



Fig. 81. — Sorghum jaelds abundant grain and forage. Kansas. 



316 The Principles of Agronomy 

economic question. It may not be profitable as a general 
practice in the United States, but it is in many dairy 
sections. 

351. Soiling crops. — Any one crop is not ready for 
soiling for more than one or two weeks. A series of crops 
needs to be carefully arranged in order to keep green feed 
constantly on hand. In alfalfa districts, this one crop 
can be kept ready throughout the entire season except 
in early spring, when it is watery. An alfalfa field mowed 
part at a time until full bloom is reached can be mowed 
over in the same order, yielding nearly mature feed for 
the remainder of the summer and fall. Alfalfa is, more- 
over, the best soiling crop known, because of its high- 
yielding power, its palatability, and its high protein con- 
tent. It cannot be surpassed in districts where it grows 
successfully. 

Green cereals cut in the milk, corn fodder, grasses, peas, 
soybeans, millets, sorghums, vetches, rape, clover, and 
cowpeas are used separately and in combination. A vari- 
ation in time of planting changes the time of maturity 
to considerable extent, thus lengthening out the period 
of usefulness. A series of small areas may be planted to 
various crops so selected, planted, and arranged as to 
give a constant supply of green forage. As soon as the 
early crops are used, they should be resown or others 
planted to prevent the land's lying idle. Roots may 
assist in autumn. 

SUPPLEMENTARY READING 

Meadows and Pastures, J. E. Wing. 

Farm Grasses of the United States, W. J. Spillman. 

Field Crops, Wilson and Warburton, pp. 379-390, 301-306. 

Field Crop Production, G. Livingston, pp. 370-380. 

Forage Crops, Voorhees, pp. 34-41, 311-327. 



Pastures, Meadows, and Soiling Systems 317 

Cyclopedia of American Agriculture, Vol. II, pp. 434-456, 569-574. 
Reseeding of Range Pastiu"e Lands to Cultivated Forage Crops, 

U. S. D. A. Bulletin, No. 4. 
Forage Plants, C. V. Piper, pp. 67-113. 
U. S. D. A. Farmers' Bulletins: 
No. 66. Meadows and Pastiu-es. 

72. Cattle Ranges of the Southwest. 
102. Southern Forage Plants. 
147. Winter Forage Crops for the South. 
361. Meadow Fescue. 

502. Timothy Production on Irrigated Land in the North- 
west. 
509. Forage Crops for the Cotton Region. 



CHAPTER XXV 
SORGHUMS AND MILLETS 

The sorghums and millets, a comparatively new and 
rather distinct kind of crop, have recently come to notice 
in the semi-arid sections of the United States. The 
United States Department of Agriculture found them 
growing in similar regions of the Old World and intro- 
duced them here as worthy of trial. The millets spread 
rapidly for a time. The sorghums are now replacing 
them slowly but surely save in a few districts. 

Both are by nature dry-weather crops, oflFering possi- 
bilities on the dry-farm and even under irrigation. Peren- 
nial forage crops are favored in the West largely because 
of alfalfa's being so extremely well-adapted. In spite of 
this, there seems to be a need for annual drouth-resistant 
crops. 

SORGHLTM (Holcus, oT Andwpogon, Sorghum) 

352. Origin. — No one will ever know exactly just 
where the group of plants we know as sorghums orig- 
inated. Some evidence suggests Africa as the starting 
point, but other facts likewise indicate an independent 
origin in India. Many wild grasses, closely allied to the 
domesticated members of the family, are found growing 
wild in Africa — more, in fact, than in any other part of 
the world. The sorghums are shown in Figs. 80, 81, 
and 82. 

318 



Sorghums and Millets 



319 




320 The Principles of Agronomy 

As crop-plants, sorghums are as old as any known. 
In Egypt they were grown when history was first re- 
corded. They soon spread into Asia as far as Manchuria. 
Notwithstanding this, the Greeks grew no sorghum ; 
neither did the Romans until shortly after the Christian 
era, when an importation from India took place. 

As far as American experience is concerned, the history 
of the crop is brief. In 1853 Chinese sorgo (whence the 
word as we have it) was brought from France. In 1857, 
the United States Department of Agriculture introduced 
varieties from every part of the world where much was 
grown. The national government also encouraged the 
spread and trial of these varieties. Rather constant 
development has since followed in the regions adapted 
to the particular members of the family brought here, 
although the crop has not as yet become a major one. Its 
possibilities are potential rather than realized, that is, its 
promises are extensive, but its records narrow, on account 
of its having had but little chance to prove itself. 

353. Relationships. — Sorghums belong to the grass 
family, being in many respects closely related to maize. 
Johnson-grass {Holcus halepensis) is a bad weed in the 
warmer parts of the United States. Vigorous rootstocks 
are largely responsible for the pestiferous habits of this 
plant. Not all Johnson-grass has rootstocks, since a 
few varieties of it are annuals, spreading only by seed. 
Then comes Sudan-grass and Tunis-grass, which resemble 
Johnson-grass and vary toward the sorghums. All of 
these are annuals, lacking rootstocks which cause peren- 
nial rooting habits. Sudan-grass seems to occupy a 
place of intermediate improvement between Tunis-grass 
and the cultivated sorghums. 

354. Description. — Corn is so much like sorghum 
that by the ordinary person they would be mistaken for 



Sorghunis and Millets 321 

one another in early growth. Their root-systems are 
similar save that no brace roots are sent out by sorghum 
and that corn roots to a slightly greater depth. Three 
to four feet seems to be the commonly accepted depth 
for sorghums. An elaborate net-work of roots, however, 
occupies the first fifteen to twenty inches of soil. 

Sorghum stems are jointed and filled with pith which 
in some varieties bears juice rich in sugar. The height 
varies from two to a dozen or more feet, but four to eight 
feet is common. Ordinary sorghum is usually not less 
than one inch or more than two inches in diameter. 
Stalks sucker readily, especially if cut before they are 
mature. 

The leaves are not so abundant as on corn, but they 
are thicker and show a decided tendency to roll into 
upright cylinders in severe drouths. Rolling probably 
lessens transpiration materially by reducing the surface 
that is exposed to evaporation. Leaf sheaths, in some 
cases, clasp the stem well beyond the next node, present- 
ing a more continuous covering than does corn. 

After the tasseling period, sorghum dift'ers widely from 
maize in appearance and growth habits. Xo ear develops. 
Its tassel flowers are perfect and the grain develops in 
the head, which may be a compact, spike-like aggregate 
or an open, broom-like panicle anywhere from three to 
thirty inches, — sometimes drooping, sometimes erect. 

The main stem branches into a number of pedicels, 
which branch again. Seed, borne at the end of these, 
is rather globular and hard. In color, it varies from 
white through yellow, brown, and red to nearly black. 
Some kernels are flattened while others are almost spheri- 
cal. Some varieties have seed less than one millimeter 
in diameter, others nearly a centimeter. 

These variations are widest between the tj^pes used for 



322 The Principles of Agronomy 

different purposes. Just as corn varieties fall into six 
groups, or types, sorghum varieties naturally group them- 
selves into three distinct types according to the purpose 
for which they developed. 

355. Varieties. — Though other classifications are often 
made, the sorghums are commonly classified as (1) sweet 
sorghum, (2) grain sorghum, and (3) broom-corn. 
Particularly adapted for sirup, grain, or whisk production, 
each type is used for forage and grain. On account of 
the comparative infancy of the industry, sorghum pro- 
duction has not become nearly so specialized as corn- or 
fruit-growing in regard to selection of varieties for different 
purposes; yet, there is a general adaptation of varieties 
that cannot be ignored. 

Sweet, or saccharine, sorghum is grown primarily for 
sirup and sugar. For that purpose, sorgo, as it is called, 
was brought to the United States. The sudden growth 
of the beet-sugar industry, however, offered a more eco- 
nomical means of procuring sugar. Shortly afterwards 
sweet sorghum proved the most valuable type for forage. 
The sweet sap seems to give it a palatability not found 
in other groups. The stalks are fine and leaves more 
abundant than in other kinds. The seed is small, with 
distinct red or dark brown color and borne in loose pani- 
cles. Amber, Orange, and Sumac are the most exten- 
sively-grown varieties ; Red Amber, Planter's Friend, and 
Gooseneck are also worthy of mention. 

Those varieties used for grain have little, if any, sweet 
juice in the pith, and they are coarser than the sac- 
charine type. Shorter nodes, fewer leaves, larger kernels, 
and more clear-cut sheathing characterize grain sorghums. 
The heads are generally compact and white, yellow, or 
dark brown. Kafir, milo, feterita, durra, shallu, and 
kowliang are most common varieties. Milo and kowliang 



Sorghums and Millets 323 

mature earlier than kafir — in about ninety to one hun- 
dred days. Not only are the kernels used for grain, but 
the fodder is used to some extent for forage. 

Broom-corn is distinguished by the long brush on which 
small seed is borne sparsely. Since this type is grown 
for whisk, the length and evenness of the pedicels are 
primarily important. Standard broom-corn, which is 
generally about twelve feet tall, bears brush from eighteen 
to thirty inches long. A shorter brush from twelve to 
eighteen inches in length is produced on a smaller plant 
which is known as dwarf broom-corn because of being 
only four to six feet in height. 

356. Distribution and adaptation. — As might be 
expected from a plant of tropical origin, sorghum is nat- 
urally adapted to a region of warmth and abundant sun- 
shine. By choice of varieties or from having been grown 
for centuries in arid regions, it has come to prefer a dry 
atmosphere. Greatest yields are, of course, obtained 
where moderate moisture is available, but it can be suc- 
cessfully produced in comparatively dry districts. It is 
rather drouth-resistant in sections similar to South Africa 
and the Great Plains section of the United States. Piper ^ 
says, " No degree of summer heat seems too intense for 
the sorghums, but they are injured both in spring and in 
fall by light frosts." 

Grain-sorghum varieties mature in such short grow- 
ing-seasons that they are able to mature in South Dakota 
and southward. Some forage varieties do well in ]\Iinne- 
sota and Ontario. Rapid growth coupled with drouth 
resistance enables this crop to produce more economical 
grain and forage than corn on the Great Plains where 
rainfall is less than twenty-five inches, though corn has 
not been replaced to any marked extent where the annual 

1 Forage Plants, p. 262. 



324 The Principles of Agronomy 

precipitation exceeds this. The best area for sorghum 
in America begins in about the same longitude as does 
that of dry-farm wheat. The considerable resistance to 
alkali that is manifested by sorghums as a class should 
also hasten the spread of the crop in arid regions. 

Nearly all arid regions of the Old World grow sorghum, 
with Egypt, South Africa, Australia, India, and northern 
China leading in total production. The order of impor- 
tance cannot be ascertained, since statistics are unavail- 
able partly because much of the crop which is used for 
forage is fed without being measured. In the United 
States, moreover, statistics are unreliable when it comes 
to details. Kansas is far in the lead, producing perhaps 
half the entire crop. Nebraska, Oklahoma, Texas, 
Colorado, and California grow small acreages. These 
states and Utah — perhaps some others — have large 
tracts of new land that could be made to produce sor- 
ghum economically. In some cultivated sections, other 
crops might be replaced profitably. Many trials by 
farmers and Experiment Stations must precede a definite 
statement as to where the crop will succeed or fail. 
Roughly, however, vast promise lies in the undeveloped 
possibilities of sorghums in dry regions west of the ninety- 
eighth meridian. This, of course, implies that selected 
varieties be tested as was suggested for corn. That some 
tropical sorghums have required more than seven months 
to mature when grown in Florida shows how essential 
the use of adapted varieties is to successful production. 

Soils should be well-drained and porous to permit root 
penetration. Sorghums have a reputation for being 
" hard on the land " by causing the crop that follows to 
yield lightly. Some persons think this is due to the power 
of the plant to dry the soil considerably below the wilt- 
ing point of other crops. Careful preparation of the 



Sorghums and Millets 325 

seed-bed lessens the injury, which may be due to an 
exhaustion of readily-available plant-food. Poor soils, 
too, are often used to grow the sorghum crop, not that 
the plant prefers naturally the difficult soils and dry 
climates, but that it is hardy under adverse conditions. 

357. Preparation of seed-bed and seeding. — In pre- 
paring the seed-bed, the same precautions are taken as 
for corn except that soil ought to be made finer. The 
best time for planting is after all danger of frost has passed 
and the soil is warm. 

Grain crops are always drilled in rows from eighteen 
to forty-eight inches apart. More often corn-planters 
are used with special plates or with holes partly stopped 
to govern the rate of seeding. Seed is dropped from six 
to ten inches apart in the row. From three to five pounds 
will plant an acre at this rate. 

Forage crops are planted either in rows or broadcasted 
at the rate of from fifteen to forty pounds an acre. Under 
.most favorable conditions two bushels are planted. 
Dwarf broom-corn is planted three feet between rows 
and two inches apart in the row, while standard varieties 
do better in rows three feet six inches apart with seed 
at three-inch intervals in the row. Uniformity of stand 
gives uniformity of brush, which is highly desirable since 
both too coarse and too fine whisks are less valuable than 
the normal. 

358. Treatment during growth. — Because seedlings 
are sensitive to soil or moisture, weeds injure them 
severely, and since they are tougher to mechanical con- 
tact than corn, more frequent and later cultivation may 
be given, and is, indeed, required. Intertillage with 
one-row cultivators keeps down weeds and mulches the 
soil until flowers appear. Listing is also practiced in some 
cases. 



326 The Principles of Agronomy 

359. Harvesting. — When fully mature, the grain crop 
is cut either with a corn-binder, with a sled -cutter, or by 
hand. Thorough drying before threshing prevents heat- 
ing of the grain. Curing is most easily accomplished in 
shocks which are built wide at the bottom to keep the 
heavy-headed grain from falling over. The bundles are 
either run through thresher or the heads run in and the 
stover withdrawn and shocked or stacked until used for 
rough feed. Occasionally the farmer heads the plants — 
particularly dwarf strains — by hand or machinery and 
threshes only the heads. The stalks are pastured or 
harvested separately. 

Yields as high as seventy bushels an acre occur, though 
twenty is more common and forty is good. In years so 
dry that corn fails, sorghum has given twelve to twenty- 
bushel yields. 

Forage is cut green, silage in the soft dough, and fodder 
just at bloom. Corn-binders cut large areas more cheaply 
than hand-labor. Hay is made sometimes by broad-» 
casting thick stands, cutting with a mower, and curing 
as grass. In this case the stems ought no{ to exceed the 
thickness of a pencil and should be cut before blooming. 

Acre-yields varying from ten to forty tons of green 
feed have been reported. Fifteen to twenty tons are 
taken off the land frequently. In cured hay or dried 
fodder, the returns net from two to eight tons in from one 
to six cuttings depending on the season and moisture 
available. 

The whisk of dwarf broom-corn is pulled from the stem 
at the upper node and removed from the field at once. 
In standard varieties, the stems are cut partly through 
two feet or so above ground and two rows bent across 
each other making V-shaped platforms, or "tables," of 
crossed stalks. The "brush," as the whisk is called, is 



Sorghums and Millets 327 

now cut off and placed on the " tables " to dry. After 
being cured in sheds, it is made into bales of 300 or 
400 pounds. Sometimes seed is allowed to ripen, but 
this lessens the value of the whisk more than it increases 
the value of the grain. In both cases threshers remove 
the seed from the brush, which is thrust against the cylin- 
der and then withdrawn. From two hundred to seven 
hundred pounds of cured brush represent ordinary returns 
from an acre. 

When grown for sirup, sweet sorghiun matures in the 
field. While still standing the leaves are stripped off; 
heavy rollers press the juice from the culms. Heat and 
settling clarify the juice of impurities. Warming in 
shallow pans concentrates the sirup to the desired con- 
sistency of 30 per cent moisture. About half or two- 
thirds of the juice presses out in a good mill, a ton yield- 
ing from 700 to 1200 pounds of juice which concentrates 
from ten to thirty gallons of sirup. From five to fifteen 
tons of stems grow on an acre. 

360. Use. — Sorghum grain is used only for stock- 
feed in America, though in Asia and Africa it is an im- 
portant human food. The grain is starchy and hard. 
Unless crushed, fed wet, or mixed with other feeds, a part 
of it escapes digestion. Eighty to ninety pounds of 
corn equal one hundred pounds of sorghum in feeding 
value. If fed alone, the grain has a constipating effect, 
which is relieved by the accompanying protein feed neces- 
sary to balance the ration. Colored seed is sharply 
bitter, due to tannin. Poultrymen prize the grain highly 
for their fowls. 

The dry stems and leaves of the sorghum make fair 
roughage. x\s silage, sorghum nearly equals corn ; as 
hay it ranks about the same as oats, wheat, or barley. 
It is cut for hay with mowers or binders. Stock may pas- 



328 The Principles of Agronomy 

ture considerable quantities of feed from green fields, 
since under favorable conditions it makes several growths 
and suckers freely. One serious danger, however, besets 
its use as pasture. After being stunted by excessive 
heat and drouth, prussic acid, a virulent poison, sometimes 
develops in the leaves or stems. This will kill stock in 
a few minutes. Exactly what conditions cause poisoning 
is not clear, but it seems that if the plant is kept growing, 
there is no danger. The dried fodder does not injure stock. 
Sirup manufacturing is not widely practiced. The 
demand for whisk supplies for the manufacture of brooms 
encourages broom-corn production. Illinois, Kansas, 
Missouri, and New York produce 80 per cent of the whisk 
crop. 

361. Enemies. — Kernel smut attacks individual seeds. 
Formalin seed treatment lessens the injury. Head smut 
covers the whole head and has not been successfully 
treated. Blight may kill the leaves. Selection of resist- 
ant varieties can probably control it. 

In Texas, the sorghum midge does considerable dam- 
age to the heads. Corn ear-worms, fall army-worms, 
chinch-bugs, and sorghum aphids do some damage. 
Wise cultivation will largely control insects and plant 
diseases as well as weeds. 

362. Storage and marketing. — The brush from broom- 
corn is marketed in a number of grades at one to six cents 
a pound depending on the length, uniformity, flexibility, 
and color of the whisk. Careful drying, sweating, and 
baling are essential in curing for quality, since the high 
moisture content renders molding and discoloration 
likely. Grain, fodder, and silage are handled as is corn, 
but very little gets to market. It is primarily a local 
crop. Not even the sirup, which is a farm delicacy and 
not a market product, gets far away. 



Sorghums and Millets 329 



SUDAN-GRASS 

363. Description. — Sudan-grass, an annual sorghum, 
a native of Egypt, came to the United States in 1909, and 
does well on the Great Plains from South Dakota to Texas. 
]\Iaturity is reached even in Canada. It stools abun- 
dantly, grows from four to ten feet in height, has the 
drouth-resistant qualities of the other sorghums, and has 
done well under irrigation in Colorado and California. 
It is grown only for hay or pasture. Sudan-grass resem- 
bles Johnson-grass save that it has no rootstocks. The 
stems are fine, leafy, and erect, producing from one to 
five tons of fair hay that any stock may eat safely, though 
the same troubles that occur with sorghum are possible 
when the second growth is pastured. 

364. Culture. — Best results are attained from sowing 
after the ground is warm enough for corn or for grain 
sorghums. Planting may be done either in rows or by 
broadcasting. Three pounds will plant an acre in rows ; 
fifteen to twenty-five pounds, an acre when drilled or 
broadcasted. Hay of the best quality is secured when 
grain is cut in full bloom. Mowers and binders are 
both used to cut the grass. Since seed yields up to 1500 
pounds an acre, and since the seeds are small, the plant is 
extremely prolific but is not a bad weed because it is only 
an annual. Care should be taken to avoid planting 
seed in which Johnson-grass is found. To prevent this, 
the seed-plots must be clean. 



MILLETS 

The millets, like sorghum, are very important in India 
and China for human food, but they have found no use 
in America except for forage. . Austria, Italy, and Balkan 



330 The Principles of Agronomy 

Europe use them extensively for forage. They grow well 
in dry, hot districts with short seasons, sometimes matur- 
ing in forty to fifty days. They do well wherever sor- 
ghum pays, and will grow farther north, but they have 
several faults which confine them to districts where sor- 
ghums cannot mature sufficiently, and which cause them 
to be used only as catch-crops when it is too late to start 
more valuable plants. More than a million acres are 
grown, but cultivation is diminishing rather than in- 
creasing. 

365. Relationship and description. — The millets in- 
clude ten different species in fi\e or more genera. The 
most common valuable type is the foxtail millet (Setaria 
italica). In this group are common, German, Italian, and 
Hungarian varieties. Other types are broom-corn millet, 
Japanese barnyard millet, and pearl millet. Foxtail 
millet is closely related to the common weed, green 
foxtail (Setaria viridis). It was cultivated in prehistoric 
times. Chinese records mention it about 2700 B.C. 

The plants are annual grasses, very leafy, growing from 
one to four feet tall. The heads are from two to eight 
inches long in rather compact spikes which in some 
varieties are distinctly lobed. The seed is yellowish, 
about one millimeter in diameter, with the hull boxed 
around the grain. Numerous bristly hairs project out- 
ward from the spike. 

366. Culture and value. — From two to four pecks of 
seed are sown to the acre, usually with drills. Row- 
planting is used occasionally for seed production. The 
slightest frosts kill millet ; hence late planting pays. 
Any time in June seems favorable. 

Quality in the hay deteriorates rapidly after full bloom, 
when the yield and quality are both greatest. For cattle, 
millet hay is about equal to grass, but is inferior to clover 



Sorghums and Millets 331 

and alfalfa. Horses suffer in several ways from contin- 
uous feeding of millet hay. Action of the kidneys and 
bowels increases ; joints swell and get lame ; bony texture 
weakens. Wisdom suggests that cattle as well as horses 
be fed mixed roughage rather than straight millet. 

Seed crops yield from fifteen to fifty fifty-pound 
bushels an acre. Just before maturity, binders cut the 
seed crop, which cures in the shock. Ripe heads shatter 
badly. Ordinary threshers are used to separate the seed 
from the straw. 

A smut attacks the seed, but it can be destro^^ed by the 
formalin treatment that is used on seed wheat. Chinch- 
bugs are fond of millet, which, for that reason, is often used 
as a trap crop to be plowed under when the insects have 
collected on the plants. 

367. Other types. — Japanese barnyard millet is 
coarser than foxtail millet, has branched heads, and is 
used for soiling, but does not cure readily for hay. It is 
grown widely for food in China, India, and other parts of 
Asia. 

Broom-corn millet has a brush-like head and larger 
seed than the common type. It grows as a cereal crop in 
Russia and also to some extent for forage. The Dakotas 
and Manitoba produce considerable, which is also used 
mostly for forage. 

Pearl millet, sometimes called penicillaria, is twice as 
large as other millets, has a rather woody stem filled with 
dry pith, and bears seed in a compact cylindrical head 
from which it has been called cat-tail millet. It is rather 
coarse and dry for hay. In the South, its immense 
yields of green forage make it and teosinte, another annual 
very similar to corn, popular for feed. As much as fifty 
tons to the acre of green fodder has been cut in one season 
from each of these crops. 



332 The Principles of Agronomy 



SUPPLEMENTARY READING 

The Corn Crops, Montgomery, pp. 279-342. 

Field Crops, Wilson and Warbiirton, pp. 258-263, 336-347. 

Cereals in America, T. F. Hmit, pp. 382-399. 

Field Crop Production, G. Livingston, pp. 221-238. 

Forage Plants, C. V. Piper, pp. 260-304. 

Forage Crops, E. B. Voorhees, pp. 37-131. 

Forage and Fiber Crops, T. F. Hunt, pp. 111-120. 

Southern Field Crops, J. F. Duggar, pp. 231-247. 

Cyclopedia of American Agriculture, Vol. IL pp. 384-388, 469-474, 

574-582. 
U. S. D. A. Farmers' Bulletins : 
No. 101. Millets. 

174. Broom Com. 

288. Kafir Corn. 

322. Milo. 

448. Better Grain-sorghum Crops. 

458. The Best Two Sweet Sorghums for Forage. 

552. Kafir as a Grain Crop. 

605. Sudan Grass. 



CHAPTER XXVI 

FIBERS AND MISCELLANEOUS CROPS 

The world is so wide ; soils are so different ; climates 
vary in so many respects ; there are so many kinds of 
plants with varying habits of growth that the plants 
grown for the use of man and beast are almost without 
ninnber. 

FIBERS 

Both the plant and the animal kingdoms furnish fibers 
which are used largely for clothing, carpets, rugs, ropes, 
nets, cordage, and bags. Vegetable fibers consist almost 
entirely of cellulose, while animal fibers have sufficient 
nitrogen in them to give off, when burnt, an odor char- 
acteristic not only of wool and silk, but of hair and flesh. 
A white ash remains after the burning of vegetable fibers, 
but animal fiber burns to a crisp char that usually curls. 

Vegetable fibers may be woody, bast, or floral. The 
wood and bast fibers are borne in the interior of the plant, 
bast in the inner bark, and wood in the deeper tissues of 
the fibro-vascular bundles. Bast fibers such as flax and 
hemp, and floral fibers such as cotton are by far more 
important for textiles than the wood fibers. Leaves also 
yield some fiber, as in the case of sisal and manila hemp. 

COTTON {Gossypium hirsutum) 

368. History. — Cotton cloth is cheap and practically 
all people wear some cotton. This has not always been 

333 



334 The Principles of Agronomy 

the case. A century ago wool and silk were the common 
textiles. 

Cotton had been grown for centuries in China and for 
a shorter period in India and Egypt, and being a native of 
the New World, for an unknown period of time in Peru 
and other parts of America. Not until the beginning of 
the nineteenth century, however, did it count for much 
as a world crop. Introduced into the Southern States, it 
thrived and was cultivated on a small scale before the 
Revolution. Washington and Jefferson grew it with the 
help of slaves who separated the lint from the seed by 
hand. When Eli Whitney's cotton-gin proved successful, 
cotton-growing spread rapidly. It has supported most 
of the people in the South, supplied a livelihood for 
millions in northern factories, and helped to build an 
immense foreign trade. On the other hand it was one of 
the big factors in intensifying the misunderstanding that 
led to the Civil War. 

369. Relationships. — Hollyhock is the most common 
plant that is closely related to cotton ; the mallows are 
also in the same family. In the same genus are five 
species of cotton: (1) Upland, (2) Sea-island, (3) 
Egyptian, (4) Peruvian, and (5) Bengal, or Indian. Of 
these long- and short-fibered upland or long- and short- 
staple cotton comprise most of the commercial fields in 
America. Some Sea-island is grown, however, in the 
tidewater regions, particularly in Georgia. The chief 
difference in the species is length of fiber, which varies 
from one-half inch in short-staple to two and one-half 
inches in Sea-island, long-staple producing a fiber of 
intermediate length. 

Altogether there are several hundred varieties of cotton. 
These are grouped into eight types or variety groups : (1) 
Cluster, (2) Semi-cluster, (3) Rio Grande, (4) King, (5) 



Fibers and Miscellaneous Crops 335 

Bigboll, (6) Long-limbed, (7) Intermediate, and (8) Long- 
staple Upland. These names, in general, indicate growth 
habits or growth regions. Jackson, Hawkins, Peterkin, 
Layton, Toole, King, and Allen Long-staple are standard 
varieties. 

370. Description. — Cotton has a deep-rooting habit, 
but also sends numerous horizontal branches in the upper 
three inches of soil. The stem is solid, woody, consider- 
ably branched, and from three to six feet long. The 
leaves are broad, three-lobed, and palmately-veined, 
while the flowers are usually white or yellowish contain- 
ing a pistil with a divided stigma and a compact group 
of stamens bearing waxy pollen. Though naturally 
cross-fertilized by insects, the flowers are capable of self- 
fertilization. Small stems arising from the main branches 
or sub-branches bear the flowers and later the boll, which 
is a heavy pod containing the lint and embedded seed. 
Under a microscope, mature lint shows a definite tw^ist- 
ing, perhaps due to drying of the tubular fiber. This 
twist roughens the surface of the lint strengthening the 
grip one fiber gets on another when it is made into thread. 
Each fiber, a single cell, is a product of the flower. It 
surrounds the seed, which is about one-fourth inch in 
diameter. A coat of oil that covers the lint must be re- 
moved before cotton is dyed or before it is made into 
absorbent cotton. 

371. Adaptation. — Cotton will grow in most soils ; 
clays and loams, moderately dry and well-drained, are 
most favorable. Moderate moisture and frost-free 
seasons from six to seven months in duration encourage 
the best growth. Because these conditions exist in the 
Southern States as nowhere else, it is this section that 
produces most of the cotton of the world. Of twenty 
million 500-pound bales, the United States produces 12 



336 Tfw Principles of Agronomy 

million, India 4 million, Egypt 1.3 million. The other 7 
million bales are the combined harvest of Brazil, Peru, 
Mexico, Turkey, and China. Texas, Georgia, Mis- 
sissippi, Alabama, South Carolina, Arkansas, Oklahoma, 
North Carolina, and Louisiana produce 96 per cent of 
the American crop and rank in the order named. So 
exclusively does Texas grow cotton that 40 per cent of 
her improved land is devoted to this crop. 

372. Culture. — It is a practice, common but unwise, 
to grow cotton on a field several years in succession. The 
stalks are broken and plowed under or burned. " Beds " 
are made by turning two furrows toward each other 
every three to five feet, the spaces often remaining un- 
broken until the first cultivation. Seed at the rate of 
one-half to one bushel an acre is drilled into these beds 
by a one-row planter after a shallow furrow is opened. 
When the plants are well started, dirt is thrown away 
from them and they are " chopped out " until the plants 
are left one or two feet apart in the row. From one to 
five cultivations are given, generally shallow, to avoid 
cutting the roots, which are abundant near the surface. 

Much of the cultivation has been done with one-mule 
plows and poor machinery, but recently two-row culti- 
vators, good harrows, and efficient plows have been in- 
troduced into many sections. Extensive cultivation 
without rotation and without barnyard fertilizer has 
resulted in the ruin of many fields in spite of the fact that 
lint and oil cause no drain on mineral fertility. Cotton- 
seed meal and commercial fertilizers are used to some 
extent ; diversified farming, rotation, and better culture 
are badly needed. 

Boll-weevils and bollworms have caused much damage ; 
cotton wilt and root rot, both plant diseases, injure the 
crop considerably. Better farming methods through 



Fibers and Miscellaneous Crops 337 

education of the farmers — Negro and white — will 
bring success in pest control, progress in industrial ac- 
tivities, and better citizenship. 

373. Harvesting and marketing. — As soon as the bolls 
open, men, women, and children begin picking by hand. 
Machines are used to some extent, but since the cotton 
bolls do not ripen at the same time, and since the 
machines injure the plants, they are not widely used. 
After picking comes ginning, which consists of separating 
the seed from the lint by means of revolving teeth. 

The lint is bound in bales of approximately 500 pounds 
and covered with coarse bagging. Buyers take a large 
part of the crop at harvest, although some farmers, 
singly or in cooperation, hold their crop in warehouses 
for a more favorable selling time. Previous to long ship- 
ment, the bales are pressed into about half the volume 
of the original bales. 

Variation in length of fiber causes a variation in price, 
usually from eight to fifteen cents a pound, though some 
years as little as 5 cents has been realized. In 1914, 
much of the crop could not be sold on account of a war in 
Europe cutting off a large part of our export trade of 
cotton, which ordinarily exceeds that of all other crops 
combined. 

374. Use. — Cloth factories in the United States, 
England, Germany, France, Belgium, and Holland depend 
largely on American cotton for raw fiber. Oil is also 
taken from the seed, leaving oil-cake that is valuable for 
stock-feed ; the bolls and coarser seed products mixed 
with the oil-cake and ground are used for nitrogenous 
fertilizer. A fine fuzz called linters, removed from the 
seed by special ginning, is used for making carpets and 
twine. 

Some feed value is left in the stalks, which may be 



338 The Principles of Agronomy 

browsed. Burning the stalks is bad practice, unless 
necessary in insect or disease control, because they add 
organic matter to the soil when plowed under. 

FLAX {Linum usitatissimum) (Fig. 83) 

Flax has been grown from the earliest times as a fiber 
crop. Priests used it for their robes and for wrapping 
mummies, and the people made clothing from it in both 
Palestine and Egypt long before the time of Christ. 

375. Description. — The plant consists of a slightly 
branched tap-root ; a slender stem from one to three 
feet long, either simple or branched according to whether 
it is in thick or in thin patches ; linear lanceolate leaves 
that are alternate and nearly sessile ; beautiful, five- 
parted, delicate blue flowers; or a globular pod filled 
with ten flat-oval, russet seeds rich in oil. The bast 
fiber, or linen, is separated from the stem by " retting." 

376. Adaptation. — Flax will grow on any kind of good 
soil in climates that permit the successful production of 
wheat. Russia produces two-thirds of the fiber flax of 
the world ; Austria-Hungary, France, Belgium, and 
Holland grow most of the remaining third. The crop of 
the United States, grown largely for seed, is produced 
almost entirely in the three states : North Dakota, 
Minnesota, and South Dakota. Since many states in 
wheat areas have flax-growing possibilities, the crop will 
probably spread much. Like the United States, Ar- 
gentina grows flax for seed, producing 34 per cent of the 
entire seed-crop. This exceeds the production of any 
other country. Russia is third and the United States 
second in importance. 

377. Culture. — Most of the flax crop in the United 
States is produced on newly-broken ground before any 



Fibers and Miscellaneous Crops 



339 



other crop is sown. After plowing, the land is smoothed 
and two or three pecks to the acre planted one or two 
inches deep by means of grain drills. Little treatment 




Fig. 83. — A good crop of flax seed. Wisconsin. 



before harvest is given. The seed and fiber crops are 
harvested differently. 

Seed flax is cut with a grain binder and threshed by an 
ordinary threshing machine. For fiber, the flax is pulled 
by hand, tied in bundles, and cured in shocks. The 
next process, retting, consists of spreading the stems 



340 The Principles of Agronomy 

thinly on the ground and exposing them to dew or water 
for three or four weeks. This loosens the fiber, which is 
removed by pounding with mallets or by bending in a 
machine. A thorough beating with wooden paddles 
completes the separation, after which combing separates 
the long fiber (flax line) from the short (tow). 

378. Use and value. — Linseed oil, used in the manu- 
facture of paints, varnishes, medicine, oilcloth, and 
linoleum, is extracted from the seed by crushing, heating, 
and pressing or by treating with naphtha. Residues, 
pressed into oil-cake or ground into linseed meal, are 
valuable for stock-feed. The straw contains some feed- 
ing value, and also a little brittle fiber that can be made 
into coarse bagging or used for packing in upholstery. 

Well-cured fiber makes a cloth that is valuable because 
of its strength and uniform whiteness ; because it does 
not fray in laundering as does cloth made from cotton or 
wool ; and because it takes starch well. For these rea- 
sons, linen is used for collars,, cuffs, other apparel, and for 
household articles that must be of spotless white. 

OTHER FIBERS 

379. Hemp {Cannabis saiiva), which is related to the 
mulberry and the " mock," or osage orange, yields some 
coarse fiber for ropes, burlap bagging, and matting. 
The best crops are produced in corn-growing sections that 
have a moist, fertile soil rich in lime. Though other sec- 
tions have favorable soil and climate, the blue-grass 
regions of Kentucky and Tennessee, and parts of New 
York and Nebraska as yet produce most of the crop. 

The stamens and the pistils are borne on different 
hemp plants. Staminate plants branch less than the 
pistillate, and on that account yield a better fiber. Both 



Fibers and Miscellaneous Crops 341 

kinds of plants vary from three to twelve feet in height. 
A tap root-system, a strong stem, and deeply-serrated 
leaves ending in a cluster are characteristic of the plant. 
Oval seed, about one-eighth of an inch in diameter and 
covered with a hull, are borne at the top. 

From four to six pecks of seed are sown to the acre, 
just before corn-planting season. Little cultivation is 
necessary, as the plants usually smother weeds. When 
ready for harvesting, the crop is cut with mowers and 
binders, or by hand if it is too large for machinery. The 
separation of fiber from the stem is similar to that of flax. 

380. Miscellaneous fibers. — INIanila hemp, or abaca 
(Musa te.vtilis), in the same genus as the banana, is much 
grown in the Philippine Islands for strong fiber out of 
which rope hawsers or cables, and high-grade binder 
twine are made. The plant requires abundant rainfall, 
considerable warmth, and well-drained soils. The leaf- 
sheaths of the plant furnish the fiber, which the natives 
get by scraping off the pulp. 

Sisal {Agave rigida), in the same genus as the century 
plant, furnishes a fiber used for twine and for mixing with 
manila fiber in cordage. The leaves are crushed by 
machinery to loosen the hard strands. It is not very 
useful in marine service because salt water markedly 
decomposes it. 

A niunber of other plants producing fibers are grown in 
various parts of the world : jute in India ; maguey in 
Mexico and Central America ; istle in Mexico, New 
Mexico, and Texas; and New Zealand hemp in New 
Zealand. 

MISCELLANEOUS CROPS 

Many other plants are grown wherever and for what- 
ever purpose man desires them. He cares not what family 



342 



The Principles of Agronomy 



they are in, nor what kind of plants they are, provided he 
can make some use of them. The use may in some cases 
be harmful, but this makes no difference ; if he wants the 
plant, he grows it as a crop. 

381. Cabbage {Brassica oleracea), and kohlrabi (Bras- 
sica oleracea var. caulo-rapa) are used to some extent for 
feeding in isolated districts. Kohlrabi, not widely grown 














'M^ti&.. 




'^J'« 



S'^^- 



FiG. 84. — Cabbage as a field crop. Delaware. 

in America, is an enlargement of the stem, while cabbage 
heads are massed leaves. Kohlrabi is sown, thinned, 
cultivated, harvested, stored, and fed in the same way as 
rutabagas; in yield and feeding value it is also very 
similar to the rutabaga. Cabbages are commonly sown 
in hot houses and transplanted in May or June two or 
three feet apart in hills with rows equally far apart. 
For feeding, the crops may be seeded thick in fields after 



Fibers and Miscellaneous Crops 343 

the last frost and thinned hiter. Their chief use is for 
human food, though in some sections, they are grown 
for stock-feed, yielding occasionally as high as forty 
tons of forage to the acre. Cabbage is valuable for milch 
cows, but is rather difficult to cure ; as pasturage it 
serves both cattle and sheep very well. A cabbage field 
is shown in Fig. 84. 

382. Rape (Brassica Najms) grows from two to four 
feet tall sending out many broad, succulent leaves in 
early growth. Sown broadcast at the rate of three to 
five pounds an acre, it will keep down weeds ; it yields 
most in rows two to three feet apart. It may be sown 
in late spring or during early summer either alone or with 
grain. Sometimes it is planted two or three weeks after 
grain, leafing out abundantly when the grain is cut. 
Sometimes it is sown between corn rows after cultivation 
has ceased. It is valuable for hog or sheep pasture, but 
is not cured for dry forage. Yields are rather heavy. 
Dwarf Essex is the usual variety. 

383. Kale (Brassica oleracea), a headless cabbage, 
furnishes considerable winter soiling in the coast region 
of Washington and Oregon, being cut for green feed 
during the mild winter. The yields vary from ten to 
thirty tons of green forage an acre, with fifteen to twenty 
tons common under fa^'o^able conditions. This slightly 
exceeds the yield of rape. Since all the mustards feed 
heavily on mineral food of the soil, fertilizer is beneficial 
in considerable quantities. Farm manure in the West 
and commercial fertilizers in the East and in the Old 
World are used to supply these demands. 

384. Enemies. — Although intensive culture should 
easily control the weeds, some insects and the disease 
club-root, common to the whole family, are by no means 
easily eradicated. The club-root (PInsmodlorpha hrassi- 



344 The Principles of Agronomy 

cce) fungus develops inside the root, distorting it and 
causing the plants to die. The spores live in the soil 
awaiting a chance to attack other roots. Long rotation 
is the only method of control known for soil once infested. 

The cabbage-root maggot (Pegomyia brassicoB) lays 
its eggs near the root, and the maggot riddles the root 
causing the plants to look sickly and then to die. One 
method of control is to place a spoonful of carbon 
bisulfide in the soil four to six inches from the plant, and 
to compress the soil tightly over hole. The liquid be- 
comes gas and penetrates to the maggots. 

Paris green or arsenate of lead, used as for potato bugs, 
that is, sprayed on young plants, aids greatly in control- 
ling the green cabbage worm {Pieris rapoe). Plowing as 
soon as the crop is removed also helps considerably. 

.The cabbage aphis {Aphis hrassicce) feeds on the leaves 
and but for parasitic enemies would be decidedly injuri- 
ous to all crucifers. It is best handled by thorough 
spraying with tobacco solution (" black-leaf 40 ") one 
part in four hundred of water. 

Flea-beetles, cabbage loopers, cabbage webworms, 
cross-striped cabbage worms, diamond-back moths, and 
cabbage curculios do damage in various ways. The 
method of control is largely one of prevention by means 
of culture and rotation. Any good manual gives insecti- 
cide treatments. 

TOBACCO {Nicotiana Tabacum) 

Some plants have always supplied man with drugs 
which he has chosen to use for remedies, stimulants, or 
narcotics. Opium and cocaine were used for a long time 
to soothe, stimulate, or deaden nervous response. After 
the discovery of America, tobacco became the chief 



Fibers and Miscellaneous Crops 345 

sedative plant, and it has gradually come into use the 
world over. People smoke or chew it, or use it for snufF. 
It finds some use as an insecticide and germicide, but this 
is of minor importance compared to its use in satisfying 
the " tobacco habit." The alkaloid poison nicotine is 
responsible for its narcotic effect on the nervous system. 

385. Distribution. — Extreme sensitiveness to soil con- 
ditions limits the production of tobacco to small areas. 
Each of the several types thrives only on a certain kind 
of soil. Isolated districts from Connecticut to Texas 
produce tobacco, but more than half of the crop of the 
United States is grown in Kentucky, Virginia, and North 
Carolina. 

386. Culture. — Virgin soil or sod land is most favor- 
able for tobacco cultivation. Even on these, however, 
the plants are transplanted from seed-beds, which are 
necessary on account of the extreme smallness of the seed. 
The soil for the seed-bed is thoroughly fined and usually 
sterilized to a depth of three or four inches by burning 
brush or logs on it. Weed seeds are thus killed. In 
March or April, the seed is broadcasted crosswise and 
lengthwise of the seed plot to insure even distribution. 

When the plants are nine or ten weeks old, they are 
transplanted from one to three feet apart in rows two to 
four feet apart. Frequent cultivation keeps down weeds 
and at the same time mulches the soil. During growth, 
the upright stem and upper leaves are cut off to stimulate 
growth of the remaining leaves. Both field and shade 
culture are practiced. Shading consists of a framework 
over which is placed thin cotton or laths short distances 
apart. These shut out a part of the light, thereby causing 
the leaves to be thin and soft. 

387. Curing and marketing. The leaves are either 
pulled separately as they ripen or harvested all at once 



346 



The Principles of Agronomy 



by cutting the whole plant. Curing requires steady dry- 
ing that keeps the leaves pliable. Large barns are filled 
with the leaves hung over laths. Slow fires are often 
used to hasten curing in wet weather. 

When well cured, the leaves are uniformly brown and 
not brittle. On a damp day, they are stripped off the 
stem and tied in bundles. These are later made into 
larger bundles and allowed to " sweat." If warehouses 
are near, the loose bundles are sold, but if shipping is 
necessary, the tobacco is packed in large hogsheads. 
Since carefully-graded leaves bring the best price, con- 
siderable care is exercised to separate leaves of different 
quality and to place only one grade in a package. 

388. Sugar-cane. — About half the sugar of the world 
is made from sugar-cane (Saccharuvi officinarimi), which is 
produced only in tropical and semi-tropical countries. 




Fig. 85. — Planting sugar-cane. Louisiana. 



Fibers and Miscellaneous Crops 347 

Britisli India, Cuba, Java, and Hawaii are the chief pro- 
ducers. Louisiana and Texas produce all that is grown in 
the United States. Alluvial soils along the lower Mis- 
sissippi supply abundant moisture and, therefore, pro- 
duce good yields. 

Sugar-cane, which is a perennial, has plume-like tassels, 
bears no ears, has buds at the nodes, and resembles corn 
in size, nature of stem, leaves, and root-system. The 
buds grow when the stalks are covered with moist 
earth, as they are when a new crop is started (Fig 85). 
After planting, sufficient cultivation is given to control 
weeds. 

Chemical analyses indicate the time for harvest by 
showing when the sugar content is highest. The cane is 
stripped of its leaves, topped in the field, and cut close 
to the ground with large knives. Since the sugar content 
lowers soon after cutting, the cane is taken at once to the 
factory, usually on cars. Heavy rolls crush the stalks, 
squeezing out the juice, which is made into sugar by much 
the same methods as beet juice. 

389. Sweet potatoes. — Most of the sweet potato 
{Lpomoea Bafotas) crop of the United States is grown in 
the South. Loose, friable soils favor best growth of the 
enlarged roots which are the edible plant parts. Cultiva- 
tion is very similar to that given " Irish " potatoes. 
Shoots from the roots are transplanted for a new crop 
(Fig. 86). Since frost injures the crop readify, the plant is 
harvested before cold weather sets in. 

Sweet potatoes are used almost entirely for human 
consmnption, forming in the South a more important 
article of diet than the common potato (Fig. 87). They 
are fed to hogs to some extent and the fields are used 
for pasturing hogs, which are turned in to " root " out the 
potatoes. 



348 The Prijiciples of Agronomy 




Fig. 8G. — Sweet potato plants wtartetl in a phint- 




Fiu. 67. — In the South sweet potatoes are an important crop. 



Fibers and Miscellaneous Crops 349 

390. Fruits. — Apples, peaches, pears, cherries, citrus- 
fruits, and small-fruits are all grown extensively in various 
parts of the country on such large areas that they might 
rank as field crops, though, of course, they are classed 
as horticultural products. Formerly, they were grown 
in small plots, but with more extensive culture their 
problems are akin in some respects to grain and forage, 
differing, however, in pruning, spraying, thinning, pack- 
ing, and marketing. 

Irrigation, cultivation, and fertility of orchard soils 
depend on the same principles that influence farm crops. 
Weeds must be kept down by plowing between the trees 
or by using cultivators (Fig. 89) ; the soil must be kept 
in good tilth by the addition of farm manure or the plow- 
ing under of cover crops. Clovers are probably best for 
this purpose. In some cases, at least, it seems advisable 
to have the rows in sod instead of bare. 

391. Truck crops. — In the neighborhood of canneries, 
large acreages of tomatoes are grown under contract. 
This crop is usually transplanted from hot-beds and 
cultivated much as potatoes until harvest season, when 
the tomatoes are picked by hand and hauled to the fac- 
tory. 

Peas, beans, cucumbers, cauliflowers, and other garden 
crops are grown near factories for canning purposes, or 
near large cities that afford ready markets. Cantaloupes 
and melons are also grown under peculiarly favorable 
conditions and shipped or hauled to market. 

Squash and pumpkins are grown on many farms for 
use in the house, or for cattle- and hog-feed. They are 
usually planted in hills five or six feet apart and culti- 
vated as long as the vines permit. When the vines die 
from frost or from maturity, the squash and pumpkins 
are gathered and stored under cover. 



350 The Principleft of Agronomy 




Fig. 88. — Greenhouse crops are in demand near large cities. 




Fig. 89. — A good implement with which to cultivate on a large scale. 



Fibers and Miscellaneous Crops 351 

392. Timber crop. — With the depletion of many 
forest lands, the price of lumber has risen to such an ex- 
tent that it is profitable for farmers in many localities 
to grow small patches of timber. Hardwood for repair 
of various machines and tools ought to be at hand at all 
times. In some sections, a few trees may be grown for 
this purpose and kept free from low branches by pinching 
off branch buds and by pruning wisely. 

393. Other crops. — Tea, coffee, nuts, tropical fruits, 
rubber trees, sugar maples, poppies for opium, hops, cacti, 
and dye and medicinal plants are grown to some extent 
in parts of the world. Besides these, countless plants are 
grown in small gardens for home use. Finally, the 
flower-growing industry has assumed importance (Fig. 88). 
Greenhouses and home-, roof-, and house-gardens abound 
with innumerable plants bearing beautiful flowers, leaves, 
or stems. 

SUPPLEMENTARY READING 

Cotton, C. W. Bvirkett. 

Hemp, Boyce. 

Field Crops, Wilson and Warburton, pp. 241-255, 363-386. 

Field Crop Production, G. Livingston, pp. 337-357. 

Forage and Fiber Crops in America, T. F. Hunt, pp. 304-402. 

Forage Crops, E. B. Voorhees, pp. 292-310. 

Forage Plants, C. V. Piper, pp. 589-595. 

Southern Field Crops, J. F. Duggar, pp. 248-424, 484-547. 

Cyclopedia of American Agriculture, Vol. H, pp. 221-224, 226-229, 

247-258, 281-303, 377-380, 380-384, 388-391, 494-410, 530- 

534, 554-559, 631-636, 639-656. 
U. S. D. A. Farmers' Bulletins : 

No. 27. Fla.x for Seed and Fiber. 

36. Cotton Seed and its Products. 

47. Insects Affecting the Cotton Plant. 

48. The Manuring of Cotton. 
164. Rape as a Forage Crop. 



352 The Principles of Agronomy 

209. Controlling the Boll Weevil in Cotton Seed and at 

Ginneries. 
211. The Use of Paris Green in Controlling the Cotton 

Boll Weevil. 
217. Essential Steps in Securing an Early Crop of Cotton. 
223. Miscellaneous Cotton Insects in Texas. 
226. Building up a Run-down Cotton Plantation. 
274. Flax Culture. 

276. The Advantage of Planting Heavy Cotton Seed. 
290. The Cotton Bollworm. 
302. Sea-Island Cotton. 
314. A Method of Breeding Early Cotton to Escape Boll 

Weevils. 
333. Cotton Wilt. 
344. The Boll Weevil Problem. 
364. A Profitable Cotton Farm. 
433. Cabbage. 

500. The Control of the Boll Weevil. 

501. Cotton Improvement Under Weevil Conditions. 
512. The Boll Weevil Problem. 

519. An Example of Intensive Farming in the Cotton Belt. 
577. Growing Egyptian Cotton in Salt River Valley, Ari- 
zona. 
601. A New Method of Cotton Cultm-e and its Application. 
625. Cotton Wilt and Root-Knot. 



CHAPTER XXVII 
IMPROVEMENT OF CROPS 

Though our crops are far superior in many respects to 
those of our ancestors, there still remains room for un- 
dreamed-of improvement. Every farmer knows he will 
have some small and some knotty potatoes ; that some of 
the wheat will shrink or lose color, become smutty or 
lodge and rust ; that some ears of corn will be nearly 
bare, and that most ears will not be entirely filled with 
deep kernels. Regardless of its care, a farm returns 
lower yields some seasons than others ; no matter how 
much caution is used in cultivation and selection of seed, 
poor stands in some parts of the field will be found. The 
farmer knows that his yield from each acre is never so 
large as it might have been had not the unexpected or 
the unavoidable happened, or had the field been handled 
a little differently. That much can be done to improve 
crops is apparent. A plant-breeding field is seen in Fig. 
90 and a hand thresher in Fig. 91. 

Experience has proved that careful cultivation, rota- 
tion, manuring, and irrigation may increase, and even 
double the yields in some cases. These gains last only 
for a short period of time, that is, until the effect of the 
extra care has passed. Next year it must be repeated 
to secure the extra yields. If plants could be found that 
would produce more, simply because they were higher 
2 a 353 



354 The Principles of Agronomy 

yielders, whatever increase came might be expected year 
after year. Nor would this bar the opportunity for 
improvement by superior cultural methods; indeed, it 
often happens that the better the plant the more readily 
it responds to additional care. 

Hunt ^ estimates that if grain plants could be obtained 
that would produce one additional kernel in each head or 
on each ear, the total yield of the United States would 




Fig. 90. — Breeding nursery for timothy. (Pennsylvania Experiment 

Station.) 

increase by 5,000,000 bushels of corn, 15,000,000 bushels 
of oats, and 1,500,000 bushels of barley. One additional 
potato in each hill would total 21,000,000 extra bushels 
of potatoes. 

394. What is improvement ? — Perhaps the most im- 
portant thing in crop improvement is increase in yield. 
Better quality also deserves attention in that it increases 
the usefulness and market price of the product. Clean, 
uniform potatoes free from disease are much sought after, 
particularly for seed. Growers would pay extra for them. 
1 Cereals in America, pp. 14-15. 



Improvement of Crops 



355 



Plump wheat of uniform texture; soft, leafy hay; or 
apples alike in color, flavor, and size bring extra prices. 
Both yield and quality are resultants of several complex 
factors. They are ends — goals toward which improve- 
ment must be pushed. Not always can this be done 
directly, for it may be that one factor alone, such as disease 
in potatoes, is hindering. Improvement in yield or quality 




Fig. 91. — Hand thresher for work in plant-breeding. 

is most often made by looking back to find the cause of 
the defect. One muddy tributary will discolor all the 
river below its entrance ; if this is cleared, the whole 
stream is clear. If a crop lacks resistance to drouth, 
to heat, to frost, to insects, to disease, to alkali, or to 
water, it may be injured seriously any time by a single 
weakness, though it has strength in all other respects. 
" A chain is no stronger than its weakest link." 



356 The Principles of Agronomy 

Should a variety of corn from a section with a long 
growing-season be brought into a district with a shorter 
one, it could not mature ; and whatever its possibilities 
in other respects, not much will actually come from it. 
Though climatic adaptation is paramount, general suit- 
ability to soil and cultural methods is also essential. 
Potatoes succeed best on loose, fertile soils and under 
clean cultivation. A selection of adapted varieties is 
the first step toward better crops. Experiment stations 
are continually testing crops to find the strains best 
suited to their localities. 

395. Ideal sought. — Improvement consists largely of 
advancement toward some desired quality in a given 
crop. The factors that determine best growth are tools 
of the plant-breeder who can wield them effectively. 
This he can do only when he knows where to strike and 
how. We have much to learn about plant-breeding, but 
even if we knew all, no great gains could be made unless 
the breeder had an ideal plant clearly in mind. Just as 
an architect sees and always works to build the house he 
has in mind, so must the plant-breeder know just what he 
desires. Nor must the ideal change. Imagine the kind 
of house a person would have if he changed his mind each 
week while he was building it. If his ideal is wrong, he 
will come out wrong ; if he has a good plan, he will come 
out right, provided he does not change. So it is with the 
plant; the first ideal must be right, then all effort must 
bend toward it. But this ideal may be impossible or 
so nearly so that it is not feasible. We can hardly hope 
to grow grass that is all leaves, but we can accomplish 
much in reducing the percentage of stem. The ideal 
sought should be possible, valuable, distinct, and constantly 
striven for. 



Improvement of Crops 357 

METHODS OF IMPROVEMENT 

Crops may be improved by three general methods : (1) 
better culture, (2) attention to the purity and strength of 
seeds, and (3) plant-breeding, which consists of selection 
or of crossing and selection. 

396. Cultivation. — Though farm methods have im- 
proved very materially since the Civil War and even in 
the last few years, many farms do not get cultivation 
that comes up to the best knowledge of the owners, much 
less up to the standard urged upon them by agricultural 
colleges and farmers' organizations. A more systematic 
practice of the care and use of farm manure, good plowing, 
early spring harrowing, wise rotation, moderate irrigation, 
clean farming, treatment for insects and plant diseases, 
harvesting in the proper way and at the proper time all 
deserve attention. A systematic practice of these well- 
known cultural methods will improve both the yield and 
the quality of farm crops. In any kind of farming the 
best results cannot come without proper attention to 
these principles. 

397. Seed-testing. — Whether the farmer raises or buys 
his seed, it is almost sure to contain some impurities, such 
as broken kernels, seed of other crops, dirt, chaflF, and weed 
seed. A mixture of varieties prevents marketing to best 
advantage where it does not hinder in other ways, while 
broken kernels, dirt, and chaff may cause poor crop stands, 
thereby lowering yields and affording opportunity for 
weeds to get started. Weed seeds introduce undesirable 
plants into the field. These usually cause a decrease 
in the desirability of the harvest as w^ell as a decrease in 
yield, to say nothing of the extra labor entailed in con- 
trolling the pests. Noxious weeds new to the district 
or to the farm are frequently introduced into fields, causing 



358 The Principles of Agronomy 

endless difficulty and perhaps making impossible the 
profitable production of some crop. Russian thistle, 
bindweed, quack-grass, perennial sow-thistle, Canada 
thistle, and milkweed are a few weeds especially hard to 
eradicate that may be thoughtlessly introduced in impure 
seed. 

In addition to impurities in the seed there may be some 
that lack the power to germinate or lack the necessary 
strength to send up vigorous plants. Since it is desir- 
able to know what kind and how much impurity seed 
contains, and its relative power to grow, it is essential 
to test samples before sowing. 

In order to do this, small quantities of seed from several 
parts of the sack or bin should be mixed thoroughly and 
divided into halves, one of which should be repeatedly 
mixed and divided until a representative sample small 
enough to test is secured. With the help of hand forceps, 
needles, and a hand lens a separation of the sample into 
five piles may be made : (1) good seed, (2) dirt and chaff, 
(3) other crop seed, (4) broken kernels, and (5) weed seed. 
By carefully weighing the separates, the tester can deter- 
mine the percentage of purity, and by comparing the 
weed seed with samples in a collection, he can find out to 
what weeds they belong. The next step is to test the 
viability, or germinable power, of the pure seed. To do 
this a plate half full of moist sand is covered with a piece 
of white cloth or blotting paper, and 100 or 200 seeds are 
counted out on it. After placing another plat^ on top 
to prevent drying, the plates are set in a warm place. In 
a few days the seeds that have germinated may be counted 
and recorded. Repetition of the counting every day for 
a short period will show the percentage of germination. 
By referring to tables of purity and of germination stand- 
ards, one may find out if the seed is worth planting. 



Improvement of Crops 359 

398. Reproduction. — A seed is the mature, fertilized 
ovary of a plant and the connecting link between two 
generations of plants. The parent plant grew and 
developed partly in order to produce seed that it might 
leave another generation of similar plants. Flowers in 
plants seem to be primarily for this purpose. A perfect 
flower consists of calyx, corolla, stamens, and pistil, but 
many plants have only the last two parts, which are the 
important ones, since from them the seed develops. 
Pollen from the stamens alights on the stigma of the 
pistil and under favorable conditions sends a long tube 
down the style to the ovule. The union of the pollen 
and ovary causes a union of the male gamete in the 
pollen with the female gamete in the ovule. This process, 
known as fertilization, begins the life of the seed which, 
when mature, consists of (1) a miniature plant or embryo 
surrounded by (2) a quantity of stored-up food, both 
of which are in turn inclosed in (3) a membranous cover- 
ing called the hull. Since each seed is capable of be- 
coming a plant, the number of descendants a parent 
plant may have depends on the number of seeds it can 
produce. This varies from a few hundred in the case of 
some crops to a quarter of a million or more in the case 
of large Russian thistles or tumbling mustard. 

399. Variation. — Mere chance would cause some of 
the many descendants to differ from others, but the law 
of variation causes each individual to differ frota every 
other. Just as no two people are alike, no two plants 
are alike. They differ in color, size, shape, rooting, flower- 
ing, and in numerous other ways. Oats always bring forth 
oats, but there are no two oat plants that do not differ. 
One among several thousand will do best in particular 
surroundings. It is upon this principle that both natural 
and artificial selection depend. 



360 The Principles of Agronomy 

400. Natural selection. — Because some one plant out 
of thousands is more fitted to survive in its particular 
surroundings, that one plant will grow most vigorously. 
Now, if all the seeds from any one kind of plant grew, 
this plant would soon fill the whole earth. Therefore, 
in the end, not many more individuals can live next year 
than do this year without crowding out others. Since 
only a few of all the descendants of a plant can possibly 
survive, those most fit live and the remaining ones die. 
Thus nature constantly improves the wild plants by 
unending, relentless selection. For countless ages, only 
the most fit of whole races have endured to rear descend- 
ants, which in turn are culled out by ever increasingly 
rigorous selection. The longer this weeding out of the 
weakest continues, the better adapted the survivors are 
to cope with their enemies. All our bad weeds origi- 
nated in the Old World where, for thousands of years, 
they have been struggling for existence in cultivated 
fields. This long, incessant struggle to retain foothold 
has developed their means of survival. 

401. Artificial selection. — Because man has put his 
crop-plants in unnatural surroundings, they have lost the 
fitness acquired before they w^ere domesticated. The new 
struggle thus set up causes many variations which afford 
opportunities for selection. With an ideal in mind, man 
can improve these plants if he continues to select rig- 
orously and unerringly from many generations of 
plants grown in the same environment. This is one reason 
why home-grown seed is better than imported. His ideal 
must not change nor must his grip weaken by unwise 
choosing. Only the best can be tolerated. 

Although the method of procedure looks simple, con- 
siderable difficulty is encountered in deciding just which 
individual plant is best. For example, the hill of potatoes 



Improvement of Crops 361 

that yields most cannot always be taken as the best hill 
for parent stock because experiment may prove that it 
lacks the power to transmit its yielding qualities. Fre- 
quently this happens. The hill that maintains high 
average yields among its progeny is the one to be desired. 
Breeding plats are conducted according to this principle. 
A number of desirable hills are chosen as a starting point. 
When harvested the average size of hill and total yield 
are recorded. Next year each hill is planted separately 
and a record kept to show the pedigree of each mother 
plant. This is repeated year after year until sufficient 
data is on hand to enable the breeder to choose a strain 
that maintained the best average yields for a number of 
years. Since the poorest are constantly dropped out to 
make room for the best, the choice gradually narrows to 
a few. The same method of selection can likewise be fol- 
lowed with small-grains, corn, grasses, and other plants. 
402. The best plants should be chosen. — In all cases 
it must be remembered that the whole plant is the unit 
of selection. One kernel of wheat is as good as any other 
kernel from the same plant, for each seed will tend to 
produce a plant like the one from which it came. Of 
course, if a stool of wheat or a stalk of corn has more room, 
better soil, or more favorable conditions in which to 
grow, it produces more than one not so favored. On 
this account, it is not fair to judge plants in different con- 
ditions against each other, because it is impossible to tell 
how much is due to greater food, moisture, or room and 
how much to superior qualities in the plant itself. There- 
fore, field selections ought to be made in such a way as to 
choose plants that produce exceptionally well in spite of 
the fact that they had no advantage whatever. This 
gives a starting point for a breeding plat at an experiment 
station or for a seed plat on the ordinary farm. 



362 Tlie Principles of Agronomy 

403. Variety tests. — Much is being accomplished on 
experimental farms by testing in rows or in plats the 
yielding power of the numerous varieties of crops in order 
to find out the one best adapted to climate, soil, and 
cultural methods of the district. Since out of twenty 
or more varieties some must be best, variety tests prom- 
ise much. 

The United States Department of Agriculture has 
broadened this work by keeping in the field a number of 
men to look for new crops or new varieties of common 
crops that promise to do well in some section of the 
United States with similar soil and climate. Turkey 
red and durum wheats exemplify such introductions. At 
experiment stations, new varieties are tested for a number 
of years before they are recommended to farmers. Many 
crop plants are found unsuited and are rejected ; but a 
few have been valuable. In general, crops from southern 
Europe do well in California, from middle Europe in 
the Central States, and from the arid Steppes of Russia, 
in Great Plains areas. 

404. Steps in breeding. — There are then three steps 
in breeding : 

(1) Inducing variation. 

(2) Selection of most promising variations. 

(3) Testing the selections to find out their power of 
transmitting desirable qualities to progeny. 

405. Crossing. — Besides changing the food, the mois- 
ture, the heat, or the cultural relations of a crop, a person 
may induce variation by artificially bringing the pollen 
of one plant in contact with the pistil of another. Some 
plants, such as corn, are naturally cross-fertilized, while 
others, such as oats, wheat, and barley, are naturally 
self-fertilized ; but this makes no difference in the effect 
of crossing. In either case a widely-variant progeny 



Improvement of Crops 363 

will result in a few generations. This offers new starting 
points for selection. 

406. Mendel's law. — If pollen from flint corn fertilizes 
dent, or if dent pollen fertilizes flint, the resulting kernels 
all look flinty. Let this corn be so planted next season 
as to be protected from further crossing, and about one- 
fourth of the corn will be dent and three-fourths flinty. 
The dent will always breed true but the flint will continue 
to produce some dent and some flint. A third part of 
the flint will breed true, but it is hard to tell which part, 
since all three-fourths appear to be flint, but only one 
part is pure flint. The corn that is harvested the fall after 
the cross is made has both characters in it but appears 
to be flint, that is, the flint character is dominant and the 
dent character recessive. 

Let F represent the flint character, D the dent char- 
acter, and .r the nature of the cross-pollination. F.vD 
gives FD. Next year FDxFD gives 1 FF : 2 FD : 
1 DD. One-fourth of the corn, FF, and one-fourth, 
DD, are pure and will breed true. Half is FD, or hy- 
brid (contains two characters), and will " break up " 
next year into 1 FF : 2 FD : 1 DD. The union of the 
two characters is called combination and the later separa- 
tion is known as segregation. Most characters of plants 
seem to go in pairs behaving as F and D in the example 
cited. They are then known as unit characters. This 
law of breeding may be stated thus : When two plants 
each having one of a pair of unit characters are crossed, 
the two characters form a combination in which both 
are present but in which the dominant character hides 
the recessive ; and that in the next generation the domi- 
nant, the hybrid, and the recessive used will segregate 
out in the proportions of 1:2: 1 , respectively. It is 
called Mendel's law, after its discoverer, Gregor Mendel. 



364 The Principles of Agronomy 

By the help of Mendel's law, breeders can tell something 
as to what the results of a cross are likely to be. Natu- 
rally, this has helped much in breeding work, but many 
things not yet understood stand in the way of rapid prog- 
ress. One of these obstacles is that some plants like 
potatoes do not propagate by means of seed but by buds. 
In these cases, only straight selection can be used, since 
crossing is impossible under ordinary farm practice, 
though the true seed of potatoes is sometimes made to 
produce new variation by crossing. 

407. Importance of large numbers. — Since plants do 
not cost much, thousands of them may be bred. Only a 
few animals can be discarded on account of their great 
value, but with plants, all save one or two out of thou- 
sands may be set aside. Because of this, greater rapidity 
in plant than in animal-breeding may be expected. Why 
then the poor development of plant-breeding? First, 
sexuality in plants was unknown until recently ; secondly, 
animal-breeding began with the dawn of history and 
plant-breeding only two hundred years ago ; thirdly, the 
male animal can be controlled, while pollen of plants, 
which blows everywhere, can be controlled only with the 
utmost difficulty. Much has been done, however, by 
selection and variety-adaptation tests. 

408. Better seed. — Plant-breeding farms occasion- 
ally send out desirable strains of some crop. Frost- 
resistant fruits have introduced fruit-growing in districts 
where it was hitherto impossible; rust-resistant carna- 
tions, cantaloupes, and small-grains decrease losses in 
many sections ; seedless oranges and grapes are boons to 
the fruit industry ; corn that ripens in short seasons allows 
this crop to be grown northward ; frost-resistant alfalfa 
is now widely grown in the northern Great Plains where 
this crop previously became winter-killed. 



Improvement of Crops 365 

By the methods outlined in the treatise of each crop, 
farmers may get better seed. Assistance from the state 
and from the national government should help them. 
Careful attention to seed-testing, seed selection, and seed 
treatment will hasten the day of better seed and better 
crops. 

"It is a time-worn but none-the-less true saying that 
good seed is essential to good agriculture. No matter 
how well the farmer prepares his land, no matter how 
much time, labor, and money he spends on it, if much or 
all of his seed fails to grow he will either have a poor crop 
or be obliged to reseed, thus losing time and labor." ^ 



SUPPLEMENTARY READING 

Plant-breeding, Bailey and Gilbert. 

Plant Breeding, Hugo De Vries. 

Domesticated Plants and Animals, E. Davenport. 

Cereals in America, T. F. Hunt, pp. 14-24. 

Cyclopedia of American Agriculture, Vol. II, pp. 53-69, 141-144. 

Book of Alfalfa, F. D. Coburn, pp. 27-43. 

Forage Plants, C. V. Piper, pp. 46-65. 

The Corn Crops, E. G. Montgomery, pp. 85-93. 

Corn, Bowman and Crossley, pp. 447-479. 

Selection of Seed Wheat, G. W. Shaw. California Bui. No. 181. 

Wheat Breeding, E. G. Montgomery, Nebraska Bui. No. 125. 

U. S. D. A. Farmers' Bulletins : 

No. 382. The Adulteration of Forage-Plant Seeds. 

428. Testing Farm Seeds in the Home and in the Rural 
School. 

1 Coburn, The Book of Alfalfa, p. 27. 



CHAPTER XXVIII 
WEEDS 

Natural selection has been operating so long that some 
plants are able to hold their ground against natural com- 
petitors. Weeds have survived not only against other 
plants but against man, who, by cultivation, has attacked 
them in new ways and in new places. They have survived 
in spite of man's effort to eradicate them. His effort to 
surround crops with conditions favorable to their growth 
has made the fight against weeds in cultivated ground 
still more relentless. On the other hand, crop-plants 
have been unfitted for competition by constant care and 
protection. Wheat, for example, would probably dis- 
appear in a few years, if it were left to take care of itself. 

This ever-increasing keenness of competition makes 
weeds more and more fit to maintain themselves. Vari- 
ous, indeed, are the methods they have adopted. To 
overcome them, man first must learn their ways : to find 
a weak place in their armor is his hope. New tools, new 
methods of cultivation, and the application of sprays 
are only attempts to send against a weed an enemy 
whose methods of attack the weed is not prepared to 
face. The farmer must know the nature of the weed he 
is attempting to control ; what it can and cannot with- 
stand ; and how best to strike into its weakest part. 

409. Definition. — Weeds are simply plants growing 
where they are not wanted, — nuisances to the farmer in 
handling any particular crop or piece of land. Alfalfa 

36G 



Weeds 367 

in potatoes and volunteer wheat in beets are as distinctly 
weeds as are the common pigweeds or foxtail. Sometimes 
the crop-plants themselves stand so thickly upon the 
land that they crowd each other out by shading or by 
competition for moisture. Much damage comes to dry- 
farm wheat in this way, which causes larger losses than 
appear at first glance. Apples and peaches must be 
thinned to insure large fruit. When one apple limits 
the size or quality of another, it is a weed. 

Some persons maintain that ugly plants are weeds, 
and only ugly ones. Morning-glories are not ugly but 
they are abominable nuisances. Sagebrush is ugly, but 
it is valuable in its natural home. Some persons regard 
as weeds only those plants that have flowers which do not 
attract attention. The flowers of the small-grains, for 
instance, are not at all noticeable, while morning-glories 
and Canada thistle, two of our worst weeds, have 
showy flowers. Others consider plants that spread rapidly 
to be weeds. This is usually the case. Below are two 
commonly-used definitions, but they probably make no 
clearer statements than the one given : (1) "A plant 
which interferes with the growth of the crop to which the 
field is temporarily devoted," (2) " Any injurious, 
troublesome, or unsightly plant that is at the same time 
useless or comparatively so." 

410. Classification. — As regards length of life, weeds 
may be classified as annuals, winter annuals, biennials, 
and perennials according to whether they live one, two, 
or more years. This is, perhaps, the most useful as well 
as the most comprehensive classification made, for in it 
are all weeds, and upon it depends the method of eradica- 
tion. Another useful grouping is to name the families, 
such as grasses, mustards, composites, and legumes. 
The objection to this system is that annuals and peren- 



368 The Principles of Agronomy 

nials often occur within a family, and hence demand 
different treatment. To tell whether a weed is an annual 
or a perennial suggests the general method of control. 
Both systems of naming are helpful and should, therefore, 
be used. 

411. Occurrence. — No farmers are exempt from weed 
pests. They occur everywhere ; they grew even in 
Eden. Ever since, they have been spreading far and 
wide by the numerous and ingenious methods that they 
have transmitted to the next generation, or that they 
have since acquired in the struggle for existence. So 
thoroughly has nature done the work that no spot has 
escaped. 

At the doorstep, they creep out from the edge of the 
stone or out of a crack ; along the pathway, they cover 
all ground not constantly trodden ; in waste places, they 
mar the landscape; in crops, they crowd and struggle 
for supremacy ; and even in the cemetery, they grow from 
the graves of the dead. It is only the living man with a 
hoe or a plow that they respect ; only from him do they 
hide their heads, and then, not until he uses sharp edges. 
Nor do they lack persistency ; let him leave a single root, 
and though they languish for a time, if he does not find 
the solitary root by which they cling to the soil and to 
life, they take a fresh hold and before he is aware, have 
tightened the grip until he realizes that he has lost his 
opportunity of easy conquest. 

Not only do they persist in the soil, but they feed on 
other plants as parasites. The dodder twines about the 
alfalfa, sucking the sap ; the mistletoe does the same on 
trees. Plant diseases are largely due to plant parasites. 

The first year that virgin land produces a crop, some 
weeds creep in. Soon they trespass in large numbers. 
In a forest region devoid of common weeds, let a fire lay 



Weeds 369 

bare a section of land. The first year it will teem with 
plants not found in the neighborhood, the seed of which 
was either dormant in the ground, or was brought long 
distances by wind or water. The seed seems, like bacteria, 
to float in the air, though this is, of course, not the case. 

412. Dissemination. — Weeds do, however, come from 
so many sources that it is impossible to tell the origin of 
every particular one. The sources of weed introduction 
may be summarized as follows : 

(1) The seed of the crop itself often contains seed of 
noxious plants, such as cockle in wheat ; wild oats in oats ; 
trefoil, clover, and pigweeds in alfalfa ; and Canada blue- 
grass in Kentucky blue-grass. 

(2) Manure frequently carries hard-shelled seeds. Pig- 
weeds, mustard, cocklebur, and sunflower are frequently 
scattered in this way. 

(3) Irrigation and run-off water carries the seeds of 
nearly any weed, for practically all will float. 

(4) The wind wafts light, winged seed, like those of 
thistle, dandelion, and milkweed, for great distances, 
and rolls tumbleweeds, such as Russian thistle, over long 
stretches. 

(5) Railroads have introduced many of our most serious 
pests, including Russian thistle. Steamships likewise 
carry them across ocean and river, which are naturally 
impassable barriers. 

(6) Animals carry burs about in their hair or wool. 
Burdock is a notorious example of a hobo stealing a ride 
on a hair cushion ; neither is cocklebur negligent of such 
opportunities. They travel first class. 

(7) While eating the fleshy covering of wild berries, 
man scatters many plants by dropping the seed where 
he ate the delicious fruit. 

(8) Man also mixes harmful seed with grain that he may 

2b 



370 The Principles of Agronomy 

get more profit when the grain is sold. Often he does this 
innocently, but he has been known to do it willfully. Much 
sweet clover seed has been mixed with alfalfa because the 
clover was worth less on the market pound for pound. 
Canada blue-grass seed has been imported to adulterate 
that of Kentucky blue-grass. 

(9) Settlers have introduced, for medicinal properties, 
new plants, which have later proved to be unmitigated 
nuisances. Burdock and hoarhound have been coaxed 
across the continent, coming perhaps as herbs from 
Europe. 

(10) Finally, a few weeds scatter their own seed by 
means of miniature explosions generally caused by a pod 
bursting, as in some of the vetches. The squirting cu- 
cumber accomplishes the same purpose by the rind keeping 
rigid and forcing the seeds out. 

413. Losses from weeds. — Exactly what are the losses 
due to weeds, is usually extremely hard to estimate. In 
some cases, they steal plant-food and in others moisture 
from the crop-plants. In addition large weeds shade or 
crowd out the smaller useful plants. One or all of these 
injuries may result at any time. In the West, however, 
the loss of water is the most serious, since, upon the 
moisture depends the quantity of crops produced, that is, 
water is the limiting factor. Badly-infested farms lose 
much in selling values on account of weeds. They can be 
cleansed only at great expense in cash, labor, crop loss, 
and time. Paint adds more to the price of a building 
than the cost of material and application ; weeds detract 
more from the price of land than the cost of eradication. 
They are eye-sores. Some farms have suffered so much 
that they will not bring the owner any reasonable price ; 
they are unsalable. Coe ^ cites an instance where land 
1 South Dakota Bulletin, No. 150. 



Weeds 371 

valued at $150 to $200 could not be sold because it was 
infested with horse nettle. 

Some weeds are poisonous, causing loss by the killing 
or the weakening of stock. Larkspur, loco, and water 
hemlock do this ; other weeds taint milk, or render animals 
unclean ; burs injure wool to a considerable extent. 

Besides these direct injuries to the crop, the farmer suf- 
fers other losses no less important. Weeds may carry 
plant diseases or shelter insect pests. A troublesome dis- 
ease of cotton also attacks numbers of common weeds 
which keep the fungus alive until it finds another oppor- 
tunity to attack cotton. Alfalfa leaf- weevil is sheltered 
during the winter in dead weeds and rubbish of any sort. 

Many weeds are a great hindrance in harvesting. They 
clog grain-binders, potato-diggers, and other machinery. 
Containing much moisture, they prevent crops from curing 
properly. In marketable products, extra labor is re- 
quired to remove such foreign matter. Moreover, when 
the crop sells, the buyer docks in price or weight, or in 
both, far beyond the actual damage, on account of the 
presence of dry stems, seeds, odor, or taste due to im- 
purities. Here is a direct money loss. 

The most noticeable of all difficulties with weeds is that 
in their removal, incalculable labor is expended yearly. 
If cultivation had no other purpose and performed no other 
service than the killing of weeds, the loss would be enor- 
mous, but cultivation benefits the crops by loosening and 
mulching the soil, and perhaps in other ways. A crop that 
is one-third weeds increases the labor of handling it by one- 
half. Here is a loss seldom reckoned, but one deserving 
consideration. 

Tumbleweeds, catching in wire fences, lodge there in 
numbers sufficient almost to hide the fence lines. Strong 
and even moderate winds exert immense pressure on this 



372 The Principles of Agronomy 

increased surface, tugging and straining on the wire, 
loosening posts in soft ground, and pulling staples. In 
addition to being unsightly, these weed accumulations 
when dry increase the possibility of disastrous fire. 

Finally, some students maintain that weeds exert a 
moral stress on the farmer. From one viewpoint it does 
seem reasonable that the neglect of weeds may extend to 
other things. More reasonable, perhaps, is the idea that 
the weeds would not be allowed to over-run the farm, 
if the carelessness were not already present. If, however, 
there be a moral loss in addition to the one hundred million 
dollars due to damage of crops in the United States an- 
nually, the harm is, indeed, astounding. 

414. Prevention. — Let us glance at the vital, practical 
phase — eradication. The sources of seed, the structure 
of the weed plant, and the nature of the injury are all 
factors in determining the method of control. 

Here, as anywhere else, prevention is primary. Seed 
must be clean ; let the farmer and seedsman look well to 
that. It is fundamental. Then the farmer should exer- 
cise wisdom in hauling manure from yards where contami- 
nation is likely. If ditch banks and fields are clean, water 
will carry but few weed seeds. Let roads and fence lines 
be cleared ; horses and sheep cannot then carry " stickers." 
If man is careful, there is no need of seed scattering from 
cars, ships, or food products. These last, however, re- 
quire the wisest kind of inspection and legislation, with the 
legislation cut to a minimum. Inspection and education 
are the most hopeful avenues from which aid is expected. 

In a large measure, the problem of eradicating weeds 
must be handled by the community, that is, by the 
farmers as a group in a cooperative unit. Under the 
direction of the county farm demonstrator, the farmers 
that are not already organized should cooperate to combat 



Weeds 373 

weeds, especially new weeds which could be exterminated 
rather easily on account of their small nimiber. Canada 
thistle is spreading through entire sections, where it might 
be held at bay. Then everybody must be alive to recog- 
nize new menaces. Here is a field for county " agents," 
agricultural teachers, students, and farmers who have some 
technical knowledge. 

To assist the farmers who try to control weeds, a law 
compelling, at least, the mowing of weeds previous to 
seeding should be in force. The law must, of course, 
carry with it a penalty severe enough to make it effective. 
A law alone is of no avail. Unless a representative part 
of the community is living the law, offenders will not be 
punished. In such cases the law becomes dead, and worse 
than useless. Only the minority can be driven or de- 
terred by a law ; the majority must make and enforce 
it. Good farming comes first, cooperation, second ; a 
general enlightenment, third ; force and penalty have 
places only after these have served. 

415. Eradication. — Meanwhile farmers must culti- 
vate ; especially while the weeds are young, since they 
are then killed much more easily than later. To exter- 
minate annuals, which seed every year, only reasonable 
culture methods are necessary. To prevent their seed- 
ing is the crux of the whole matter. This eliminates 
them automatically, as soon as all the seed in the soil has 
germinated, which, however, may not be for years. To 
gain control of biennials, two years instead of one are 
required, for the plant forms seed two seasons. Plowing 
or cutting below the crown will kill them. Winter 
annuals, beginning growth in the fall, need attention 
during the autumn and early spring. Ordinary culti- 
vation destroys these three kinds of weeds. 

It is, however, with perennials that most difficulty is 



374 The Principles of Agronomy 

encountered. Some part of the plant lives a number of 
years. Leaves and seed-stems grow up from root-crowns 
or rootstocks each year. These parts are generally 
so deep in the ground that they are hard to reach. Dan- 
delions and mallows are examples of plants propagated 
by root-crowns. Rootstocks are underground stems cov- 
ered with buds, any one of which will grow. The 
leaves have dwindled into scales hiding buds which send 
out both stems and roots. This is the difficulty with 
morning-glories, salt-grass, Canada thistle, quack-grass, 
rushes, and sedges. 

The roots will eventually starve if they are not fed. 
The leaves feed the roots ; therefore, no green part is to 
be allowed above ground. It is necessary to rotate with 
crops that will smother them by shading, or that will 
permit constant cultivation. The rootstocks ought to 
be plowed in the fall, thus giving frost a chance to " get 
in a good lick." Constancy alone can prevent pests 
gaining strength ; leaves above ground soon become green. 
The chlorophyll makes food for the storehouse that 
must be exhausted. A besieging fleet would not consider 
letting an occasional ship-load of supplies pass the block- 
ade. When a strict blockade has weakened the enemy, 
then is the time to strike. In the control of weed pests, 
the course is identical. Weeds are most easily killed 
immediately after they germinate, before they can es- 
tablish a root-system. This is the best time to attack 
them, since their lease on life is now weakest. Harrow- 
ing will both root out the plantlets and bring other seeds 
near the surface where they find conditions favorable to 
begin growth. 

It is nearly as essential to germinate the seed that is 
in the soil as it is to kill the weeds. Though all seeds 
lose vitality in time, some live a number of years in the 



Weeds 375 

soil. Among these are mustard, cocklebur, and other 
hard-shelled seed. 

If, for any reason, weeds are not attacked when only 
a few days old, cultivation should not be delayed longer 
than necessary. As some plants seem to be weaker 
during blooming, this may be a good time for attack. 
It is, in that seed has not yet formed. Delay beyond 
blooming period is likely to be fraught with serious con- 
sequences, for some weeds mature seed very shortly 
after the blossoms disappear. Some flowers of a plant 
may show at the same time that others contain mature 
seed. The blossom should serve as signal hung out to 
warn that seed will soon begin to ripen. 

416. General principles. — Clark and Fletcher ^ give 
the following : 

" 1. There is no weed known which cannot be eradi- 
cated by constant attention, if the nature of its growth 
is understood. 

" 2. Never allow weeds to ripen seeds. 

" 3. Cultivate frequently, particularly early in the 
season, so as to destroy seedlings. 

" 4. Many weed seeds can be induced to germinate 
in autumn by cultivating stubble immediately after 
harvest. Most of these seedlings will be winter-killed 
or can be easily disposed of by plowing or cultivation in 
spring. 

" 5. All weeds bearing mature seeds should be burnt. 
Under no circumstances should they be plowed under, i 

" 6. All weeds can be destroyed by the use of ordinary 
implements of the farm, the plow, the cultivator, the 
harrow, the spud, and the hoe. 

" 7. Be constantly on the alert to prevent new weeds 
from becoming established." 

1 Farm Weeds, pp. 15-17. 



376 The Principles of Agronomy 

" The practice of summer-fallowing land, to the exclu- 
sion of all crops throughout the season, whatever may 
be said against it, affords the best opportunity to suppress 
noxious weeds. For lands foul with persistent growing 
perennials, a thorough summer-fallow will usually be the 
most effective, and in the end, the least expensive method 
of bringing the weeds under control. 

" To keep farms free from weeds, few methods give 
such good results as a systematic short rotation of crops, 
with regular seeding down to grass or clover at short 
intervals." 

417. Herbicides have been experimented with for a 
number of years in Europe, Canada, and the United 
States. Some interesting things have been discovered 
concerning the spraying of weeds to kill them. Copper 
sulfate (blue vitriol), iron sulfate, common salt, sulfuric 
acid, slaked lime, corrosive sublimate, and several other 
compounds have given some success in different experi- 
ments. Much care is necessary or the crop is injured 
along with the weeds. If a rainstorm follows soon after 
spraying, the chemicals run off and lose their effect. 
With more knowledge of the effect of chemicals on plants 
and more care in their application, considerable help 
should be derived from the use of herbicides. 

Copper sulfate is mixed twelve pounds in fifty-two 
gallons of water ; it kills burdock, prickly lettuce, com- 
mon mustard, prostrate pig weeds, and goosefoot, ac- 
cording to experiments at the Iowa Station. 

Common salt, applied both as spray and directly to the 
soil, kills some weeds but also injures the crop-plants. 
It is most valuable on an area in which a weed is just 
starting and where the crop can be sacrificed to eradicate 
the weed. 

Carbolic acid, mixed one part to four of water, aids 



Weed^ 377 

in the control of pig weed and smartweed, and also weakens 
Canada thistle when applied either to the root or to the 
leaves. 

Corrosive sublimate, at the rate of two and one-half 
ounces to fifteen gallons of water, kills weeds, but is very 
dangerous on account of its toxicity to animals. 

Iron sulfate is perhaps the most effective of chemicals 
when used one hundred pounds to fifty gallons of water. 
It is also used as a dust spray. Dandelions, large rag- 
weed, sour dock, sorrel, hedge mustard, pepper grass, 
shepherd's purse, common mustard, bull thistle, and pig 
weed succumb to iron sulfate spray when it is properly 
applied. 

These sprays are most effective on broad-leaved weeds 
mixed with grass crops, which have small exposed leaf 
areas. Grass weeds are not killed, while useful clovers 
and other broad-leaved crops are injured. 

418. Summary. — Weeds are undesirable plants that 
are scattered in many ways, that cause various and insidi- 
ous losses, and that must be controlled by methods varied 
to meet their habits of growth. Cultivation and rotation 
are the farmer's weapons; prevention is his unfailing 
ally. He must beware of imitations. There is none 
just as good. 



SUPPLEMENTARY READING 

Manual of Weeds, Ada E. Georgia. 
Weeds of Farm and Garden, L. H. Pammel. 
Farm Weeds, Clark and Fletcher. 
Field Crops, Wilson and Warburton, pp. 522-539. 
Some Kentucky Weeds and Poisonous Plants, H. Garman, Ken- 
tucky Bui. No. 183. 
Weeds, H. S. Coe, South Dakota Bui. No. 150. 
Minnesota Weeds, Oswald and Boss, Minnesota Bui. No. 129. 



378 The Principles of Agronomy 

Weeds, Thomas Shaw. 

Farm Friends and Farm Foes, C. M. Weed, pp. 1-55. 
Cyclopedia of American Agriculture, Vol. II, pp. 110-118. 
U. S. D. A. Farmers' Bulletins : 

No. 28. Weeds, and How to Kill Them. 

188. Weeds Used in Medicine. 

279. A Method of Eradicating Johnson Grass. 

306. Dodder in Relation to Farm wSeeds. 

368. The Eradication of Bindweed, or Wild Morning- 
Glory. 

464. The Eradication of Quack-Grass. 

531. Larkspur, or "Poison Weed." 

545. Controlling Canada Thistles. 

610. Wild Onion: Methods of Eradication. 

660. Weeds and Their Control. 



PART IV 
FIELD MANAGEMENT 



CHAPTER XXIX 
PLANNING THE FARM 

In order to make a well-balanced farm business capable 
of yielding the highest returns, considerable careful plan- 
ning is necessary. Farmers are too prone to develop 
the farm enterprise along lines of least resistance, arrang- 
ing the fields in the easiest way, rather than planning 
to save time and work during all the years that the farm 
will be operated. Planning is as important in farming 
as in business ; and no good business man conducts his 
affairs without a definite scheme. 

The fact that a farmer does not know exactly how he 
wants his farm to be arranged permanently should not 
prevent his making plans. He may have to change them 
somewhat in later years, but this should be no reason for 
not working on some kind of plan in the meantime. All 
planning should be done with the future in mind. It may 
be that sufficient capital is not available to place on the 
farm all the livestock that it is capable of supporting ; 
but every farmer should plan to have some stock as soon 
as possible. Almost every farm should be planned to 
this end. Other enterprises, to be added from time to 
time, should be provided for in the plan. Some of the 
situations and appurtenances to a good farm establish- 
ment are shown in Figs. 92 to 97. 

419. Plan should be stable. — Constant changing from 
one type of farming to another with every shift in prices 

381 



382 The Principles of Agronomy 

is not consistent with good business methods. Every 
type of farming has its ups and downs, there being a more 
or less regular rise and fall in the price of all farm products, 
particularly those susceptible of rapid over-production. 
The farmer who succeeds is usually the one who stands 
by his colors until the time of adversity has passed ; he 
is then ready to reap the reward which follows his per- 
sistence. It would, of course, be foolish to continue in 
a type of farming that could never be made to pay under 
the conditions in which the farmer finds himself ; but 
he should not be induced to change on account of reverses 
that follow a temporary depression in prices. 

A series of years with high prices for any farm product 
is almost sure to be followed by years of over-production. 
When the price of potatoes is high, everybody plants 
potatoes ; this means that the price will fall. A good 
market for hogs can easily be overdone on account of 
the rapidity of their multiplication and the short time 
required for them to come to maturity. It takes a longer 
time to change the price of horses, cattle, and apples 
than that of hogs and potatoes ; but they too are subject 
to changes. Staple crops like wheat and corn that can 
be stored from one year to another and transported great 
distances are much less affected by rapid fluctuations 
in price than the more perishable or bulky products. 

As a rule, it is safer to go into the raising of potatoes 
when prices are low than when they are high, because only 
few farmers will plant potatoes during a depression. 
The farmer who plants about the same area of each crop 
every year gets the advantage of high prices as well as 
having to suffer from the low; he is usually better off 
than the farmer who changes his system every year. 
The unstable farmer is likely to make changes just at 
the wrong time. 



Planning the Farm 383 

420. Number of enterprises. — Each farmer should 
maintain enough enterprises to make sure that his income 
will not be shut off by the failure of one or two crops ; 
and still he should not have so many enterprises that no 
specialization is possible. Each farm should have a 
number of major kinds of products from which the greater 
part of its income is derived. This enables the farmer 
to learn these branches especially well and makes him 
able to compete in them. There are only a few condi- 
tions, however, where high specialization in farming is 
desirable. If a farm is located near a special market, 
or if conditions are particularly favorable to some product, 
it may pay to specialize ; but on the ordinary farm, 
diversification with a number of leading products is much 
safer. 

421. The farmstead, including the farm home and 
other buildings connected with it, is the center of the farm 
activities. It should be so located that the operations 
of the farm can be carried on with the greatest economy ; 
it should, at the same time, be a desirable place to live. 

On many farms the farmstead is located on the corner 
nearest the town. This is usually a poor location, since 
it is necessary to make many more trips to the land than 
to tow^n. For convenience in getting at the land, the 
best location is in the center of the farm ; but so many 
advantages go with having the home located next to a 
public road that this is usually a better place to build. 
Something in the ease of getting at the land is sacrificed 
for the convenience of being on a regularly traveled road. 
Where land is owned on both sides of the road, it is a poor 
practice to put barns and stables on the side opposite 
the house, since the danger from passing vehicles' is 
great, and the arrangement for convenience and beauty 
is not desirable. 



384 The Principles of Agronomy 

The farmyard should be kept neat and the various 
buildings arranged for convenience, beauty, and healthful- 
ness. As much care should be taken in planning the farm 
home as the city home, because the farmer is as much 
entitled to the conveniences of life as his cousin living 
in the city. 

422. Arrangement and number of fields. — Some of the 
farms that have been handed down from generation to 
generation have been divided and sub-divided into fields 
of various sizes and shapes, seemingly without any plan, 
until it would be impossible to adopt any definite system 
without a complete rearrangement. Farms of this kind 
should be overhauled and entirely replanned to permit 
the use of modern machinery and modern methods. A 
great deal of time is wasted on irregular fields of unde- 
sirable sizes. 

The fields should be so arranged that they will all be 
easily accessible from the farmstead. A desirable ar- 
rangement is to have one main road situated in such a 
way that it is connected with each field. This road if kept 
in good repair enables the farmer to haul large loads of 
manure to the fields as well as large loads of crops from 
them. A lane running to the pasture saves time and 
annoyance. Where one or two rotations are in operation 
on the farm, it is desirable to have all the fields the same 
size in each rotation. The number of fields should not 
be larger than necessary, since the land between fields, 
is usually wasted, and encourages the growth of weeds. 

423. Size and shape of fields. — The best size for 
fields will depend on the crop grown and a number of 
other factors. For garden crops, where most of the work 
is done by hand, the size of the field is not important ; but 
for ordinary crops, where machinery is employed, fields 
should be so large that time is not lost in too frequent 



Planning the Farm 



385 



turning. The shape of the field is more important than 
most farmers reahze. A small field can be worked to 
better advantage if it is longer than wide, because it can 
be plowed and cultivated with less turning than if it were 
square. A field with one side irregular or diagonal makes 
a great deal of extra work. 

424, Fences and ditches. — Fences that are unneces- 
sarv are a great luiisance on the farm. (1) They occupy 




Fil;. 92. — Adequate buildings add to the attractiveness of the farm. 

land that might otherwise be producing crops ; (2) they 
furnish protection to noxious weeds ; and (3) if in poor 
repair, they are often sources of injury to livestock. 
In planning the farm, as few fences as possible should 
be included ; and if the farmer wishes to rearrange his 
fields, he should not hesitate to remove old fences that 
are not needed. Neat fences, kept in good repair, add 
to the attractiveness of a farm ; while fences in bad con- 
dition produce the opposite effect. In irrigated sections, 
the arrangement of ditches to supply various fields and 
still not to be in the way and not to cause too much waste 
of land, requires considerable planning. Economy of 
2c 



886 The Principles of Agronomy 

land, neatness, convenience in handling water, and a num- 
ber of other factors must be kept in mind in planning 
ditches. 

425. Use of waste places. — Many farms contain 
patches of land that are difficult to cultivate on account 
of their topography, arrangement, or the presence of 
rocks. It often costs more to till these patches each year 
than the returns justify. Where this is the case, it is 
advisable to use the land for a permanent pasture, for 
a wood lot, or for some other useful purpose that does 
not require cultivation. 



SUPPLEMENTARY READING 

Farm Management, G. F. Warren, pp. 239-269, 365-401. 
Farm Development, W. M. Hays, pp. 96-116. 
New York, Cornell Bulletin No. 295. 
Cyclopedia of American Agriculture, Vol. I, pp. 142-161. 
Cyclopedia of American Agriculture, Vol. II, pp. 90-97. 
The Young Farmer, T. F. Hunt, pp. 9-26. 
Farm Management, F. W. Card, pp. 70-90, 198-207. 
Agricultural Economics, H. C. Taylor, pp. 117-135. 
U. S. D. A. Yearbook for 1892, pp. 343-364. 
U. S. D. A. Yearbook for 1912, pp. 343-364. 

U. S. D. A. Farmers' Bulletin No. 370, Replanning a Farm for 
Profit. 



CHAPTER XXX 
WHAT CROPS TO GROW 

Crops form a considerable part of the income of prac- 
tically every farm, whether the farmer is specializing in 
crops or in livestock. The income may be derived from 
the sale of crops or from the sale of milk and beef, which 
are crops transformed into more refined products. The 
keeping of any kind of stock is impossible without crops 
to feed them. True, feed may be purchased from the 
outside, but this greatly reduces profits. Warren, in 
New York State, found that the farmers who made most 
money always sold crops, even though they were in the 
livestock business. IVIen in the dairy business find it 
possible to raise a considerable amount of extra hay at 
very little additional expense. A farmer may have a 
hobby for livestock raising ; but to make profits certain, 
he ought, in addition to stock products, to have some 
crops to sell. 

426. Crop adaptation, — It is probable that as many 
losses in farming result each year from not raising the 
right crops as from poor culture methods. In deciding 
whether to raise a crop, it is not sufficient to know that 
it will grow ; but its relative value in comparison with 
other crops should also be taken into consideration. Too 
many farmers are satisfied to produce the crops that 
have always been raised, without making a careful study 
to see if other crops would not be more profitable. 

387 



388 The Principles of Agronomy 

In deciding what crop to raise, the cHmate, the soil, 
and the market must be taken into consideration. Most 
crops can be made to grow under a number of chmatic 
conditions, but they do best in a given zone; and it is 
working with a handicap to take them out of the zone in 
which they do best. Cotton might be made to grow in 
parts of New York State or Colorado, but in these places 
it could never compete with that produced in the Southern 
States. 

Crops have preference regarding soils also. Peaches 
and cherries will grow in a heavy clay, but they do much 
better in a sandy soil. The small-grains, on the other 
hand, do best on a heavy soil, although they will grow 
in sand. It is well for the farmer to learn the kinds of 
soil to which each crop is adapted in planning his crop- 
ping systems. 

A farm may be able to produce a given crop ever so 
well, but unless there is a profitable market, it should 
not be grown. Perishable crops must be raised near 
the place of consumption ; bulky crops for market can- 
not be produced profitably at a great distance from the 
railroad. 

427. Diversity of crops. — The value of crop rotations 
in keeping up fertility has been discussed. It is not 
advisable, however, to do as one man proposed after 
reading of the benefits of rotation : plant all his farm to 
alfalfa a few years, then plow it all up and plant to corn, 
and the next year to wheat, raising but one crop each 
year. While this procedure would give the soil the bene- 
fits of a rotation, it would lack the diversity demanded 
by good farm practice. 

A number of crops should be raised at the same time 
on the farm in order (1) to lessen risk, (2) to distribute man- 
and horse-labor more evenly throughout the season, (3) 



What Crops to Grow 389 

to use equipment more effectively, and (4) to get a better- 
distributed farm income. It may be that all the crops 
raised will not give equal returns; but the one paying 
best can be raised in as large quantities as practical, and 
the others produced with labor that would otherwise be 
idle part of the time. 

428. Crop specialties. — Under certain conditions crop 
specialties pay. For example, parts of California are 
so well adapted to the raising of oranges that no other 
crop can compete with them. Farmers under this condi- 
tion are probably justified in raising but one crop, and 
in maintaining the fertility of the soil by the use of fer- 
tilizers. Under these special conditions, it is difficult 
to have a well-balanced agriculture ; and it is doubtful 
if permanency of soil fertility can be secured with the 
intensive cultivation of these specialties. 

429. Conditions for various crops. — Each type of 
farming, as well as each particular crop, requires a special 
set of conditions. Some of the factors that determine 
what crops can be raised successfully have been discussed 
already. A summary of the requirements of a number 
of the common crops may justify attention. 

Corn requires a climate having a hot summer with 
nights not too cool. It needs a large amount of moisture 
during the period of most rapid growth, and it needs a 
soil well stocked with organic matter which cannot be 
entirely supplied through the application of mineral 
fertilizers. 

Oats grow best in a cool, moist climate. They are 
not so particular about the fertility of the soil, but demand 
that it be well supplied with moisture. If the soil is too 
rich, there is a tendency for this crop to lodge and rust. 

Barley is less particular about moisture than are oats, 
but it has many other requirements which are the same. 



390 The Principles of Agronomy 

Wheat grows over a wide range of conditions, and can 
endure much more cold weather than corn. It is also 
able to adapt itself fairly well to moisture conditions. 

Rye is adapted to cool climates. It will grow in a very 
poor soil, but does best in a soil that is fairly fertile. It 
never produces very heavy yields even under the best 
of conditions and is, therefore, not adapted to intensive 
farming. 

All of these grain crops may be grown at great distances 
from large markets as they are sufficiently concentrated 
to be shipped. Most farms can, with profit, raise some 
kind of grain for home consumption even where it would 
not pay to raise it for shipment. 

Potatoes require a rather cool climate, and do best in 
a mellow, deep soil. They need sufficient moisture to 
insure a uniform, even growth ; but their quality is 
injured if too much water is present. Potatoes are 
perishable ; hence the price is likely to be irregular. 

Mangels, sugar-beets, and other root crops require 
conditions similar to those required by potatoes. Since 
they cannot be shipped any great distance, the market 
for sugar-beets is dependent on nearness to a sugar 
factory. 

Alfalfa is one of the most profitable forage crops where 
conditions favor its growth. It requires a soil containing 
lime, ami prefers an open sub-soil. The grass crops re- 
quire cool, moist conditions for their best growth. Every 
farm should produce some forage. The kind of crop to 
raise for this purpose depends on a great many conditions, 
such as moisture, climate, soil, and the kind of livestock 
whose food it is to be. 

Cotton, sugar-cane, and rice all require a warm climate 
and other special conditions which limit their growth to 
comparatively small areas. 



What Crops to Grow 391 

The fruit-crops usually pay well if raised under the 
particular soil, climatic, and marketing conditions which 
they demand. Before planting an orchard, great care 
should be exercised to see that conditions are favorable, 
since many years may be wasted before a mistake is 
discovered. 

From the numerous crops that are available, one should 
experience no difficulty in getting a diversity of profitable 
crops for almost any conditions. 

430. Work in producing various crops. — In arranging 
a cropping system, crops should be selected which do not 
conflict with each other by requiring attention at the 
same time. As far as possible, the work should be evenly 
distributed during the year. After being planted, the 
small-grains require very little attention until harvest 
time. Corn and potatoes, on the other hand, need cul- 
tivation during the growing-season. The main work in 
raising sugar-beets comes at thinning and at digging time. 
Hay needs but little attention except at harvest. Much 
of the work in an orchard can be done during the winter. 
Thus, by proper planning, crops may be selected which 
use labor, machinery, and irrigation water at different 
times. This greatly increases the profits, by making 
returns more certain and larger, and by insuring constant 
work for men and horses. 

SUPPLEMENTARY READING 

Any book on field crops. 

Farm Management, G. F. Warren, pp. 42-103, 402-415. 
New York (Cornell) Bulletin No. 295. 
Soils, Lyon and Fippin, pp. 497-502. 
Agricultural Economics, H. C. Taylor, pp. 65-77. 
Cyclopedia of American Agriculture, Vol. I, pp. 81-109. 
U. S. D. A. Farmers' Bulletin 446, The Choice of Crops for Alkali 
Lands. 



CHAPTER XXXI 
EQUIPMENT OF THE FARM 

Farming is now an industry that is conducted largely 
by the use of machinery. There is hardly an operation 
from the planting of crops to the milking of cows that is 
not done with the aid of some kind of machine. In the 
early history of farming, practically everything was done 
by hand, and the few implements used on the farm were 
very simple. During the last century, however, there 
has been a complete revolution in this respect. With 
the invention of the grain harvester, the possibilities of 
agriculture were very greatly increased. Before this 
time the amount of grain that could be raised was limited 
to the quantity that could be harvested by the slow meth- 
ods then in use. To-day no such limit exists, since every 
operation in grain-farming can be done with machinery. 
The size of a grain-farm is limited now only by the capital 
that is available. In the other branches of agriculture, 
the use of modern equipment has wrought similar trans- 
formations. 

431. The farmer as a mechanic. — The farmer of a 
few generations ago could get along with but very little 
knowledge of machinery, since he had no machines, but 
now all this has changed. The modern farmer hardly 
does a thing without the aid of some complicated ma- 
chine. The use of these various devices requires skill 
as well as considerable knowledge of mechanism. The 

392 



Equipment of the Farm 



393 



farmer should also be able to repair his own machinery. 
He is probably working at some distance from a machine 
shop and if an implement gets out of order, considerable 
time is lost unless he is able to repair it. The expense 
of having some one else do the repairing is not so important 
an item as the time lost in waiting for the work to be 




Fig. 93. — A neat and effective gate. 



done. During the harvest season one day of waiting 
may cause a loss of many dollars. 

432. Extremes in farm equipment. — Extremes in 
the use of farm equipment are often found. One farmer 
will not buy an implement unless he is absolutely com- 
pelled to. For lack of an extra plow, he will let a team 
lie idle most of the summer even though he has land that 
needs plowing. He considers the money spent for im- 
plements wasted, when in reality the plow might more 
than pay for itself in a single month. It is very poor 
economy not to buy the implements necessary to manage 
a farm in the most efficient manner. 



394 



The Principles of Agronomy 



Some farmers go to the other extreme and buy every 
new machine and device that is put on the market. As 
a result they have hundreds of dollars' worth of idle 
equipment. The wise farmer is conservative in pur- 
chasing equipment, and buys only standard implements. 
He is not, however, afraid to purchase a machine when 
he sees that it will earn money. 

433. Machines that get out of date. — Every year 
many new kinds of machines are offered for sale. Some 




Fk;. U4. — Cement fii 



of these can safely be purchased at once, but the majority 
of new devices are only in the experimental stage when 
first put on the market. They may be good in prin- 
ciple, but probably many things about them will be per- 
fected after a few years of trial. This means that there 
will be a rapid change, and that the first machine will 
be rendered out of date by more perfect models. It is 
usually a good thing, therefore, for the farmer to let new 
equipment have a year or two of trial before he ties up 



Equipment of the Farm 395 

his money in it. Standard equipment such as wagons 
and plows seldom gets out of date. 

434. Machines that are seldom used. — Some pieces 
of equipment that seem almost necessary on the farm 
are used but few times in a season. The farmer who has 
a few acres of grain needs a fanning mill to clean the seed, 
and yet it seems a waste to have this machine idle except 
for a few days during each year. This difficulty can be 
overcome in part by the cooperation of a number of farm- 
ers in the purchase and use of such machinery. Seed 
grain can be cleaned almost any time during the year. 
This makes it possible for a dozen or twenty farmers 
to use the same fanning mill, making the expense for 
each one very slight. The same rule can be applied to 
the ownership of grain drills, harvesters, threshing ma- 
chines, and numerous other implements. 

435. Size of machinery. — The size of machinery 
must be adapted to the needs of the farmer. On the 
very large farm, it is desirable to have all the machinery 
so large that it may be operated with as little man labor 
as possible. Where fields are small, on the other hand, 
large macliines cannot be used to advantage on account 
of the constant turning that is necessary. The traction 
engine as a source of power in tillage operations may be 
used under certain conditions, but it finds no place on the 
ordinary farm. In trying equipment of all kinds, the 
farmer should consider well the sizes that will best meet 
his needs. The machines should be large enough to do 
his work, and not so large that capital is unnecessarily 
tied up in them. 

436. The duty of machinery refers to the amount of 
work done, or the area of land served, by an implement 
during one season. The duty of a mowing machine would 
be very great if it could be working the year round, but 



396 



The Principles of Agronomy 



it is used only during the comparatively brief period when 
hay is in the right stage to cut. The duty of a grain drill 
is low, because the season when grain can be planted is 
short and one implement can cover only a limited area 
of land. The duty of an implement is increased by keep- 
ing it in good working order and by running it double 
shifts during the busy season. By using lights and chang- 




FiG. 95. — Gasoline engine used for stacking hay, Wisconsin. 



ing men and teams, a potato digger may be run twenty- 
four hours in a day if necessary, thereby making its duty 
two or three times what it would ordinarily be. The 
same plan may be followed with many other implements^ 
437. Depreciation. — Every farm implement depre- 
ciates, partly through wearing out and partly through 
getting out of date. A gasoline engine built fifteen years 
ago would be worth very much less to-day, had it not been 
used at all, because many improvements have since been 



Equipment of the Farm 



397 



made. The Minnesota Experiment Station found that 
depreciation of equipment each year ranged from 12 per 
cent for threshing outfits to 3.47 per cent for grain tanks. 
Implements having compHcated machinery Hke corn 
binders depreciate much more rapidly than simple ones 
like wagons. Depreciation is dependent less on actual 
use than on the care given. Machines soon rust away 
when left exposed to the sun and storms even if they 
are not used. 

438. Caring for machinery. — The sure way to waste 
money on the farm is to buy expensive machinery and 




Fig. 96. — Cheap but effective shelter. 



leave it unprotected during all seasons of the year. Costly 
machine houses are not necessary, or even desirable. 
Some machine sheds, however, are so constructed that they 
depreciate about as rapidly as the machinery they were 
built to protect. A simple but neat shed that will keep 
out water and sun will suffice. This can be built at slight 
expense, and will pay for itself in one year if there are 
many expensive machines to shelter. 

It is a good idea to clean and repair all machinery at 
the end of the season when it is put away. All parts 



398 TJie Principles of Agronomy 

likely to rust should be oiled. If this is done, the imple- 
ment is always ready for use. The practice of repairing 
when the machine is taken out for use in the beginning 
of the season results in a great waste of valuable time. 
All machinery should be kept in a good state of repair, 
as this lessens the depreciation and increases the efficiency. 
Mower knives, plows, and other similar implements work 
much more efficiently if kept well sharpened. 

439. Suitable farm buildings. — Farm buildings, al- 
though necessary, may be considered as the non-produc- 
tive part of the farm. They are needed as protection 
for the farmer as well as for his stock, farm products, and 
machinery, yet they add nothing directly to the farm 
income. Buildings, therefore, should not be expensive, 
since they tie up capital that is needed in the more pro- 
ductive enterprises. People who know nothing about 
farming and the way its profits are obtained are likely 
to criticize the average farmer for his lack of expensive 
buildings. The farmer must be conservative in this re- 
spect, however, or his desire to make a showing in build- 
ings will cripple him in his working capital. 

There is no doubt that farm buildings could be im- 
proved in design, and that, wdth proper planning, the 
money now invested could have been better spent. The 
arrangement of farm buildings in many cases results in a 
great waste of time. The modern farmer, by the use of 
cement and other available building materials, can con- 
struct all necessary buildings at comparatively low ex- 
pense. Care in planning enables him to do much more 
with his money than if he constructed a number of small 
buildings without regard to arrangement. The impor- 
tance of convenience and sanitation have also been largely 
overlooked in the past. 



Equipment of the Farm 399 



SUPPLEMENTARY READING 

Farm Structures, K. J. T. Ekblaw. 

Farm Management, G. F. Warren, pp. 355-364. 

Cyclopedia of American Agricultiu-e, Vol. I, pp. 162-278. 

Farm Management, F. W. Card, pp. 40-47. 

Physics of Agriculture, F. H. King, pp. 223-254, 329-553. 

Farm Machinery and Farm Motors, Davidson and Chase. 

Farm Development, W. M. Hays, pp. 355-384. 

Farm Equipment, Ohio Bui. 297. 

Cost of Producing Minnesota Farm Crops, Minnesota Bui. 117. 

U. S. D. A. Farmers' Bulletins : 

No. 303. Corn-Harvesting Machinery. 

347. Repair of Farm Equipment. 

475. Ice Houses. 

481. Concrete Construction on the Livestock Farm. 

574. Poultry House Construction. 

589. Home Made Silos. 



CHAPTER XXXII 

FACTORS OF SUCCESS IN CROP PRODUC- 
TION 

One of the most difficult things in any business is to 
maintain a proper balance between its parts. There is a 
constant tendency to develop hobbies, which means that 
other phases will be neglected. A merchant had a hobby 
of keeping his store neat and clean, claiming that an 
orderly establishment attracted trade. He was so 
particular about scrubbing and putting things in order, 
that when customers came in they were neglected ; 
customers were secondary to cleanliness. He also neg- 
lected to give proper attention to buying and to other 
important parts of his business. As a result of his hobby 
and in spite of the fact that his store was a model of 
neatness, he lost most of his trade and became bankrupt. 

The farmer, unless he is careful, will give most of his 
attention to one or two phases of his business and neglect 
the others. He must be constantly on the alert to keep 
the business well organized, to have the capital all work- 
ing, to practice the right type of farming, to handle the 
crops and animals in the best way, and to market to the 
best advantage. He must recognize that successful 
farming is made up of a great many important factors. 

440. Size of farm. — In order to make a success in 
the production of crops, the farm must be of the proper 
size. High yields may be obtained, but unless a consider- 

400 



Factors of Success in Crop Production 401 

able area is farmed it will be impossible to make a good 
living. A yield of fifty bushels of wheat to the acre 
would be considered excellent ; but if the farmer only 
had five acres, the returns would furnish a scant living. 
The size of farm that is most profitable depends on a 
number of factors, one of which is the kind of crop grown. 
Ten acres of strawberries would be a large field, while a 
ten-acre field of wheat, oats, or barley would be considered 




Fig. 97. — Scattered buildings increase farm labor. 



very small. Whatever the crop, the area devoted to it 
should be sufficient to justify the attention of the farmer 
and to give him an income worth while. If the area is 
too large, it cannot be successfully handled, and returns 
will be decreased. 

441. Capital. — Farming is a business requiring capital. 

This fact is often overlooked by those who wish to 

become farmers. They buy land on credit and then 

expect the farm not only to make a living for them but 

2d 



402 T}w PrincipJes of Agronomy 

also to pay for itself in a very few years. If it does not 
do this, they say there is nothing in farming. Every one 
recognizes the fact that capital is required to enter the 
banking business ; yet more capital is often invested in 
a farm than in a small bank. 

The raising of field crops can probably be done with 
less capital than is required for any other branch of agri- 
culture. Dairying and the pure-bred livestock business 
require a large initial outlay for stock ; fruit-growing 
requires the investment of capital a number of years 
before returns are expected. Notwithstanding the rel- 
atively low capital required to raise field crops, they 
cannot be successfully produced without the investment 
of considerable money. The land must be purchased or 
rented and a suitable seed-bed prepared. Seed must 
be planted and the crop cared for during growth, then 
harvested and marketed before any returns are secured. 
Many failures occur in farming because sufficient capital 
is not available. The prospective farmer, therefore, to 
be most successful should have at his disposal sufficient 
funds to operate his farm in the most efficient manner. 

442. Proper type of farming. — The type of farming 
followed is as important to success as are the methods 
used. In every section some types pay better than others, 
and the discovery of the paying type is one of the chief 
problems of the man on the land. This has been dis- 
cussed more fully in Chapter XXX. 

443. Good management. — Farming will not pay 
under the most favorable conditions without intelligent 
management. There are so many chances for losses 
that unless good judgment is exercised failure is sure to 
result. In farming, new conditions are constantly pre- 
senting themselves; hence it is impossible to lay down 
any set rules. The farmer must be constantly alert and 



Factors of Success in Crop Production 403 

ready to adapt the method to conditions as they exist. In 
many of the industries, the work is exactly the same year 
after year, and when once learned no difficulty is expe- 
rienced. Farming, on the other hand, is never the same 
during any two years. Seasonal variations are so great 
that each day presents new problems. 

The economical use of horses and machinery — plowing, 
planting, and harvesting at the right time and in the right 
way — and marketing products to the best advantage, 
both call for the highest type of executive ability. It is 
not enough to be able to raise good crops ; they must be 
produced at a profit. This requires good management. 

444. Keeping records. — The farmer cannot, without 
keeping some kind of records, tell which phases of his 
business are most profitable. The merchant keeps books 
primarily to tell whom he is owing and who owes him. 
The farmer can usually keep account of these things 
without a set of books; but in order to tell where his 
profits came from and where the losses occur a set of simple 
farm accounts is indispensable. By doing this, he is 
able to eliminate unprofitable crops and raise only those 
giving greatest returns. Few farmers will find it advis- 
able to keep a complex set of accounts, but some simple 
bookkeeping will certainly pay. 

445. Profits to a farmer vs. jrields to the acre. — In 
discussing crop production, the idea is sometimes advanced 
that the chief aim of the farmer is to get high acre-yields. 
While high yields are desirable, they are by no means 
all that the farmer wants. His chief concern is to get 
a high total income for his year's work. A net earning 
of ten dollars an acre on a farm of 100 acres is more profit- 
able than an earning of twenty-five dollars an acre on a 
farm of ten acres. 

High yields do not always bring a high net profit for 



404 The Principles of Agronomy 

each acre. For example, potatoes usually bring actually 
less money to the farmer during a year when yields are 
high all over the country than during years of low yields. 
Methods should be adopted which give large yields ; but 
of equal importance, 'is the organization of the business 
in such a way that the farmer will receive a high total 
income even though the yield of any individual crops is 
not high. In short, the function of the farmer is not 
primarily to make his land give big yields, but to use the 
land in helping himself to get a large yearly income. The 
farm is for the farmer, and not the farmer for the farm. 

446. Profits from man and horse labor. — The farmer 
should not expect to make all his profits from the land ; 
he should also make money from the men he hires and from 
the horses he uses. Some farmers seem to think that 
money paid out for hired help is lost, whereas in reality, 
a good profit should be made on every day's labor used 
on the farm. To do this requires careful management. 
The work must be so well planned that no time is spent 
doing unprofitable jobs. Employment must be arranged 
for rainy days and other times when it is impossible to 
do the regular farm work. 

More attention is usually given to man than to horse 
labor. No farmer would think of keeping hired men if 
there was no work for them to do, but idle horses are kept 
on the place for months at a time. By providing work 
for all the horses on the farm, the cost of producing crops 
is greatly reduced. 

447. Understanding each crop. — Each kind of crop 
has its own peculiar requirements, which must be catered 
to if they are to be profitable. The farmer should 
base his practices upon a knowledge of the needs of his 
crops. He must understand that alfalfa needs a soil 
containing lime, while corn needs a soil having consider- 



Factors of Success in Crop Production 405 

able organic matter. He should also learn how fertilizers, 
irrigation water, and other factors aflfect the quality of 
the crops he raises so as to be able to produce crops 
which the market demands. To have the highest suc- 
cess, therefore, the farmer must be an observing naturalist. 

448. Markets. — It is useless to raise crops unless 
they can be sold at a profit. The ordinary farmer is a 
much better producer than salesman. He is thinking 
continuously how to increase yields, but the question of 
markets attracts his attention only once or twice a year — 
just during the marketing season. The farmer may, how- 
ever, at market-time lose more by a single unwise trans- 
action than he has made during the entire season through 
extra attention to his crops. 

A number of ways of marketing are available to the 
farmer. He may sell all his crop at wholesale to the 
dealer or consumer ; he may dispose of it through a com- 
mission man who charges a percentage for making the 
sales ; he may sell on a regular market through an auction- 
eer ; or he may retail his products in small parcels to the 
individual consumer. No one of these methods of selling 
is best in all cases. Farmers are too prone to trust to 
local markets, instead of investigating every possible 
place of sale. 

Considerable loss accompanies the storage of most 
farm products ; hence, the common practice of holding for 
higher prices is not always to be recommended. Shrink- 
age and loss often amount to more than the increase in 
price received after holding for a number of months. If 
prices are particularly low at harvest and indications 
point to a rise later, it may pay to store. The farmer 
must watch markets closely from one year to the next, 
and investigate every opportunity to market his products 
profitably. 



406 The Principles of Agronomy 

Success in crop production does not consist alone in 
doing one thing well ; it calls for good judgment in many 
distinct kinds of work. The farmer who has a fad of 
marketing, or of raising crops in a particular way, often 
neglects other important factors, and as a result falls 
short of success. The successful farmer must keep his 
business well balanced, that is, he must give to each 
phase of his Avork the attention that its importance justi- 
fies. 

SUPPLEMENTARY READING 

Farm Management, G. F. Warren. 

Rural Economics, T. N. Carver. 

Cyclopedia of American Agriculture, Vol. I, pp. 162-202. 

Cyclopedia of American Agriculture, Vol. II, pp. 81-109. 

Cyclopedia of American Agriculture, Vol. IV, pp. 215-276. 

Rural Wealth and Welfare, G. T. Fairchild. 

Agricultural Economics, H. C. Taylor. 

The Young Farmer, T. F. Hunt. ' 

Cooperation in Agriculture, G. H. Powell. 

The Farmers' Business Handbook, I. P. Roberts. 

Farm Management, Andrew Boss. 

U. S. D. A. Farmers' Bulletins : 

No. 454. A Successful New York Farm. 
621. Marketing Farm Products. 



APPENDICES 



APPENDIX A 

ADDRESSES OF AGRICULTURAL COLLEGES AND EX- 
PERIMENT STATIONS AND OF THE UNITED 
STATES DEPARTMENT OF AGRICULTURE 



When not otherwise indicated, the college and experiment station 
are at the same place. Any letter addressed to the "Agricultural 
College" or " Experiment Station," with proper post-office address, 
will reach the institution. 



Alabama — 

College of Agriculture and Ex- 
periment Station — Au- 
biu-n. 
Canebrake Station — Union- 
town. 
Tuskegee Station — Tuske- 
gee. 
Alaska — Sitka. 
Arizona — Tucson. 
Arkansas — Fayetteville. 
California — Berkeley. 
Colorado — Fort Collins. 
Connecticut — 

State Station, New Haven. 
Agricultural College and Storrs 
Experiment Station — 
Storrs. 
Delaware — Newark. 
Florida — Gainesville. 
Georgia — Experiment. 
Hawaii — 

Federal Station — Honolulu. 



Sugar Planters' Station — 
Honolulu. 

Idaho — Moscow. 

Illinois — Urbana. 

Indiana — Lafayette. 

Iowa — Ames. 

Kansas — Manhattan. 

Kentucky — Lexington. 

Louisiana — - Baton Rouge. 

Maine — Orono. 

Maryland — College Park. 

Massachusetts — Amherst. 

Michigan — East Lansing. 

Minnesota — St. Anthony Park, 
St. Paul. 

Mississippi — Agricultural Col- 
lege. 

Missouri — 

College Station — Columbia. 
Fruit Station — Mountain 
Grove. 

Montana — Bozeman. 

Nebraska — Lincoln. 



409 



410 



Appendix 



Nevada — Reno. 
New Hampshire — Durham. 
New Jersey — New Brunswick. 
New Mexico — Agricultiu-al Col- 
lege. 
New York — 

State Station — Geneva. 
College of Agriculture and Cor- 
nell Experiment Station 
— Ithaca. 
North Carolina — 

College Station — West Ra- 
leigh. 
State Station — Raleigh. 
North Dakota — Agricultural 

College. 
Ohio — 

Experiment Station — Woos- 
ter. 



College of Agriculture — Co- 
lumbus. 

Oklahoma — Stillwater. 

Oregon — Corvallis. 

Pennsylvania — State College. 

Porto Rico — Mayaguez. 

Rhode Island — Kingston. 

South Carolina — Clemson Col- 
lege. 

South Dakota — Brookings. 

Tennessee — Knoxville. 

Texas — College Station. 

Utah — Logan. 

Vermont — Burlington. 

Virginia — Blacksburg. 

Washington — Pullman. 

West Virginia — Morgantown. 

Wisconsin — Madison. 

Wyoming — Laramie. 



The United States Department of Agricultm-e is at Washington, 
D.C. One may address the Secretary of Agriculture, or write to one 
of the Divisions of the Department. The most important divisions 
are as follows : 



Weather Bureau. 

Bureau of Animal Industry. 

Bureau of Plant Industry. 

Forest Service. 

Bureau of Chemistry. 

Bureau of Soils. 

Bureau of Entomology. 



Bureau of Biological Siu-vey. 
Division of Publications. 
Bureau of Statistics. 
Office of Experiment Stations. 
Office of Public Roads and En- 
gineering. 



Some of the most important addresses in Canada are : 



Dominion Department of Agri- 
culture, Ottawa, Ontario. 
Experimental Farms, Ottawa. 



Ontario Agricultural College, 
Guelph, Ontario. 

Agricultural College, Winnipeg, 
Manitoba. 



Appendix 411 



APPENDIX B 

LABORATORY GUIDES 

Manual of Agriculture — Soils and Crops, D. O. Barto. 

A Laboratory Manual of Agricultiu-e, L. E. Call and E. G. Schafer. 

Lessons on Soil, E. J. Russell. 

The Physical Properties of Soils, A. G. McCall. 

Soil Physics I^aboratory Manual, J. G. Mosier and A. F. Gustafson. 

A Unit in Agriculture, J. D. EUif. 

Examining and Grading Grain, T. L. Lyon rand E. G. Montgomery. 

Laboratory Manual of Farm Management, G. F. Warren and K. C. 

Livermore. 
Laboratory Manual of Cereals and Forage Crops, Geo. Livingston 

and Malon Yoder. 



412 Appendix 

APPENDIX C 

FERTILITY IN FARM PRODUCE 

Approximate Maximum Amounts Removable to an Acre 
Annually 



Produce 


Pounds 


Market Value 


Kind 


Amount 


Nitro- 
gen 


Phos- 
phorus 


Potas- 
sium 


Nitro- 
gen 


Phos- 
phorus 


Potas- 
sium 


Total 
Value 


Corn, grain . . 
Corn stover . . 


100 bu. 
3 T. 


100 
48 


17 
6 


19 
52 


$15.00 
7.20 


$0.51 
.18 


$1.14 
3.12 


$16.65 
10.50 


Corn crop . . 




148 


23 


71 


22.20 


.69 


4.26 


27.15 


Oats, grain . . 
Oat straw . . 


100 bu. 
2i T. 


66 
31 


11 
5 


16 
52 


9.90 
4.65 


.33 
.15 


.96 
3.12 


11.19 
7.92 


Oat crop 




97 


16 


68 


14.55 


.48 


4.08 


19.11 


Wheat, grain 
Wheat straw 


50 bu. 
2|T. 


71 
25 


12 
4 


13 

45 


10.65 
3.75 


.36 
.12 


.78 
2.70 


11.79 
6.57 


Wheat crop 




96 


16 


58 


14.40 


.48 


3.48 


18.36 


Soybeans . . 
Soybean straw . 


25 bu. 
2i T. ^ 


80 
79 


13 

8 


24 
49 


12.00 
11.85 


.39 
.24 


1.44 

2.94 


13.83 
15.03 


Soybean crop . 




159 


21 


73 


23.85 


.63 


4.38 


28.86 


Timothy hay . 
Clover seed 
Clover hay . 
Cowpea hay 
Alfalfa hay . 


3 T. 

4 bu. 
4T. 
3T. 
8T. 


72 

7 

160 

130 

400 


9 

2 

20 

14 

36 


71 

3 

120 

98 
192 


10.80 
1.05 
24.00 
19.50 
60.00 


.27 
.06 
.60 
.42 
1.08 


4.26 

.18 

7.20 

5.88 

11.52 


15.33 
1.29 
31.80 
25.80 
72.60 


Cotton, lint 
Cotton, seed 
Cotton stalks . 


1,000 lb 
2,000 lb. 
4,000 lb. 


3 

63 

102 


0.4 
11 

18 


4 
19 
59 


.45 
9.45 
15.30 


.01 
.33 

.54 


.24 
1.14 
3.54 


.70 
10.92 
19.38 


Cotton crop 




168 


29.4 


82 


25.20 


.88 


4.92 


31.00 


Potatoes . . 
Sugar-beets 


300 bu. 
20 T. 


63 
100 


13 
18 


90 
157 


9.45 
15.00 


.39 
.54 


5.40 
9.42 


15.23 
24.96 


Apples . . . 
Leaves . . . 
Wood growth 


600 bu. 
20 T. 
I tree 


47 

59 

6 


5 
7 
2 


57 

47 

5 


7.05 

8.85 
.90 


.15 
.21 
.06 


3.42 

2.82 

.30 


10.62 

11.88 

1.26 


Total crop . . 




112 


14 


109 


16.80 


.42 


6.54 


23.76 


Fat cattle . . 
Fat hogs . . 
Milk .... 
Butter . . . 


1,000 lb. 

1,000 lb. 

10,000 lb. 

400 lb. 


25 

18 
57 
0.8 


7 
3 
7 
0.2 


1 
1 
12 
0.1 


3.75 

2.70 

8.55 

.12 


.21 
.09 
.21 
.01 


.06 
.06 
.72 
.01 


4.02 

2.85 

9.48 

.14 



' From Hopkins' Soil Fertility and Permanent Agriculture. (Ginn & Co.) 



Appendix 



413 



APPENDIX D 

COMPOSITION, AMOUNT, AND VALUE OF MANURE 
PRODUCED BY DIFFERENT KINDS OF FARM 
ANIMALS 

(Results of experiments conducted at Cornell University Experiment 

Station) 





Analysis and Value 
Manubi 


PER Ton of 


Amount and Value per 

1000 LB. Live Weight 

Per Day 




Water 


Nitro- 
gen 


Phos- 
phoric 
Acid 


Potash 


Value 
per 
Ton 


Pounds 
per 
Day 


Value 
per 
Day 


Value Per 
Year 




Per ct. 


Per ct. 


Per ct. 


Per ct. 






Cents 




Sheep 


59.52 


.77 


9.39 


.59 


$3.30 


34.1 


7.2 


$26.09 


Calves 


77.73 


.50 


.17 


.53 


2.18 


67.8 


6.7 


24.45 


Pigs . . 


74.13 


.84 


.39 


.32 


3.29 


83.6 


16.7 


60.88 


Cows 


75.25 


.43 


.29 


.44 


2.02 


74.1 


8.0 


29.27 


Horses . 


48.69 


.49 


.26 


.48 


2.21 


48.8 


7.6 


27.74 



MINIMUM AMOUNT OF FARMYARD MANURE TO 
REPLACE THE ELEMENTS ABSTRACTED FROM 

THE SOIL BY A GOOD ACREAGE OF DIFFERENT 
CROPS 

Wheat 5 tons 

Barley 5 tons 

Oats 5 tons 

Corn 7 tons 

Meadow hay 8 tons 

Red clover 12 tons 

Beans 10 tons 

Turnips 15 tons 

Potatoes 10 tons 

Cabbage 25 tons 

Carrots 10 tons 



414 



Appendix 



APPENDIX E 

WEIGHTS AND MEASURES 

Avoirdupois Weight 

16 ounces (oz.) =1 pound (lb.) 

100 pounds =1 hundredweight (cwt.) 

20 hundredweight (cwt.) . . =1 ton (T.) 

1 ton =20 cwt. = 2000 lb. = 32,000 oz. 

Linear Measures 

12 inches (in.) =1 foot (ft.) 

3 feet =1 yard (yd.) 

5^ yards, or 16| ft. . . . =1 rod (rd.) 

320 rods =1 mile (mi.) 

1 mi. = 320 rd. = 1760 yd. = 5280 ft. = 63,360 in. 







Square Measures 


144 square inches (sq. in.) =1 square foot (sq. ft.) 


9 square feet .... =1 square yard (sq. yd.) 


30j square yards 








= 1 square rod (sq. rd.) 


160 square rods 








= 1 acre (A.) 


640 acres . . 








= 1 square mile (sq. mi.) 


1 square mile 








= 1 section 


36 sections 








= 1 township (twp.) 


43,560 square feet 








= 1 acre 


160 acres . . 








= X section 



Solid or Cubic Measures 



1728 cubic inches (cu. in.) 
27 cubic feet 
1 cubic yard 
1 cubic yard 
24f cubic feet 
128 cubic feet 

1 ft. X 12 in. X 1 in. 



= 1 cubic foot (cu. ft.) 

= 1 cubic yard (cu. yd.) 

= 46,656 cu. in. 

= 1 load 

= 1 perch 

= 1 cord 

= 1 board foot 



Appendix 



415 



Liquid Measures 

4 gills (gi.) =1 pint (pt.) 

2 pints =1 qviart (qt.) 

4 quarts =1 gallon (gal.) 

31J gallons =1 barrel (bbl.) 

7J gallons water =1 cubic foot (approximately) 

1 gallon water = 8.3254 pounds 

1 U. S. gallon =231 cubic inches 

Dry Measures 

2 pints =1 quart 

8 quarts =1 peck (pk.) 

4 pecks =1 bushel (bu.) 

1 bushel = 2150.42 cu. in. 



416 Appendix 



APPENDIX F 

QUANTITY OF SEED PLANTED TO THE ACRE 

Wheat 1-2 bushels 

Oats 2-4 bushels 

Barley H-2^ bushels 

Rye 1-2 bushels 

Peas 2|-3^ bushels 

Buckwheat ^ bushel 

Tv/r- J V. i oats 1 bushel 

JVlixed hay , ^ , , , 

I peas 2 bushels 

Flax ^-2 bushels 

Corn 15-20 pounds 

Potatoes 10-18 bushels 

Red clover 8-12 pounds 

Alsike clover 6-10 pounds 

White clover 4-8 pounds 

Timothy 10-15 pounds 

Orchard-grass 15-20 pounds 

Sugar-beets 12-16 pounds 

Blue-grass 10-15 pounds 

Alfalfa 10-20 pounds 

Brome-grass 15-20 pounds 

Bur clover 12 pounds 

Sweet clover 10-25 pounds 

Mangels 5-8 pounds 

Redtop 6-8 pounds 



Appendix 



417 



APPENDIX G 
MOST COMMON WEIGHTS OF SEEDS TO THE BUSHEL 



Lb. 



Lb. 



Alfalfa .... 
Bermuda-grass 

Canada blue-grass 
Kentucky blue-grass 
Clovers . . 
Cowpea . . 



Fescue, hard 
Fescue, meadow 
Flax . . . 
Hemp . . 
Johnson-grass 
Meadow-grass 
Millet . . 
Oat-grass 



60-80 
24-36 

14-20 
14-30 
60 
56-60 

12-16 
14-24 
48-56 
40-60 
14-28 
11-16 
30-60 
7-14 



Orchard-grass 
Pea ... 
Red-top (chaff) 
Red-top (fancy) 

Soybean . . 

Timothy . . 

Vetch . . . 

Corn . . . 

Barley . . . 

Oats . . . 

Potatoes . . 
Rye ... 

Wheat . . 
Beans . 

Turnips . . 



10-18 
60 

10-14 
25^0 

58-60 

45 

60 

56 

48 

32 

60 

56 

60 

60-62 

55 



2E 



418 



Appendix 



APPENDIX H 

MEASURING RULES 

Measuring grain. — A bushel of grain contains approximately 
I cubic foot. To determine the capacity of a bin, find the number* 
of cubic feet and multiply by |, or multiply by 8 and divide by 10. 

Measuring ear corn. — It requires about two bushels of ear corn 
to make one bushel shelled. To find the capacity of a crib, find 
the number of cubic feet and multiply by f or .4. 

Measuring hay. — The quantity of hay in a mow is very hard to 
estimate accurately. The deeper the hay is, the harder it will be 
packed. Some kinds of hay are heavier than others ; the longer it 
stands the more compact it becomes. Settled hay will usually weigh 
about five pounds per cubic foot, or 400 cubic feet will weigh one 
ton. (See Appendix I.) 

Measuring land. — The easiest way to calcidate land measiu-ements 
is to figure 160 square rods as one acre. A strip one rod wide and 
160 rods long, therefore, equals an acre, as does a strip four rods wide 
and 40 rods long, or eight rods wide and 20 rods long, etc. 

A surveyor's chain is four rods long. It is divided into 100 links, 
so that all calculations are in decimals. Ten chains square equal 
one acre. 

SQUARE MEASURE EQUIVALENTS 



Sq. In. 


Sq. Ft. 


Sq. Yd. 


Sq. Rod 


Acre 


Mile 
Sq. 


144 = 


1 = 










1,296 = 


9 = 


1 = 








39,204 = 


272i = 


30i = 


1 






6,272,640 = 


43,560 = 


4,840 = 


160 = 


1 




4,014,489,600 = 


27,878,400 = 


3,097,600 = 


102,400 = 


640 = 


1 



Appendix 419 

APPENDIX I 

RULES FOR MEASURING HAY IN THE STACK 

A number of measurements are taken and the average obtained 

for : L = length, W = width, O = overthrow (a Hne is tlirown over 

the stack to the ground on the other side and the overthrow is the 

distance over the stack from the bottom on one side to the bottom 

on the other). Then the number of cubic feet in the stack may be 

found from the following formulas : 

(O 4- W) 

^^ — ^ • multiplied by itself and this product by the length of 

4 

stack = cu. ft. 

(O times W) ,. j ,^ 

times L = cu. it. 

•i 

(O - W) 
For small, low ricks use the formula W times L = cu. ft. 

2 

For round stacks, get the average circumference (C) at or above the base 
or " bulge," find the vertical height of the measiu-ed circumference 
from the ground and the slant height from the circumference to the 

top of the stack. Then use the formula 8 times (height 

100 

of the base + f slant height of top) = cu. ft. 

Wlien the niunber of cubic feet is known, this number is divided 
by the number of cubic feet in a ton to find how many tons there are. 
There are about 343 cubic feet in prairie hay that has settled 30 days 
or more, but 422 cubic feet is often considered as closer. For alfalfa 
422-512 cubic feet are used in different regions for hay that has set- 
tled 30 or more days. When the hay has settled 5 to 6 months 422 
cubic feet and after a year 343 cubic feet are usually accepted as a 
ton. For round stacks a ton visually contains 512 or more cubic 
feet after 30 days. The number to be used varies with the depth 
of stack as well as with the time of settling. 



420 Appendix 



APPENDIX J 

WHEAT HARVEST CALENDAR 

January. — Australia, New Zealand , Chile, and Argentine Republic. 

February and March. — Upper Egypt, India. 

April. — Lower Egypt, India, Syria, Cyprus, Persia, Asia Minor, 
Mexico, Cuba. 

May. — Texas, Algeria, Central Asia, China, Japan, Morocco. 

June. — California, Oregon, Mississippi, Alabama, Georgia, North 
Carolina, South Carolina, Tennessee, Virginia, Kentucky, Kansas, 
Arkansas, Utah, Colorado, Missouri, Turkey, Greece, Italy, Spain, 
Portugal, South of France. 

July. — New England, New York, Pennsylvania, Ohio, Indiana, 
Michigan, Illinois, Iowa, Wisconsin, Southern Minnesota, Nebraska, 
Upper Canada, Roumania, Bulgaria, Austria-Hungary, South of 
Russia, Germany, Switzerland, South of England. 

August. — Central and Northern Minnesota, Dakotas, Manitoba, 
Lower Canada, British Columbia, Belgium, Holland, Great Britain, 
Denmark, Poland, Central Russia. 

September and October. — Scotland, Sweden, Norway, North of 
Russia. 

November. — Peru, South Africa. 

December. — Burmah, New South Wales. 



Appendix 421 

APPENDIX K 

PRICES OF WHEAT (CHICAGO MARKET) 1863-19101 



Months of Lowest 
Prices 



Yearly Range 
OF Prices 



Months op Highest 
Prices 



August 
March . 
December 
February 
August . 
November 
December 
April 
August . 
November 
September 
October 
February 
July 

August . 
October . 
January 
August . 
January 
December 
October . 
December 
March . 
October . 
August . 
April . . 
June . 
February 
July . . 



.80 
1.07 

.85 

.77 

1.55 

1.041 

.761 

.731 

.99i 

1.01 

.89 

.811 
.831 
.83 
l.Oli 
.77 
.811 
.86§ 
.951 
.911 
.90 
.69^ 
.731 
.691 
.661 
.7li 
.75^ 
.74i 
.85 



@ 1.12i 
@ 2.26 
@ 1.55 
@2.03 
@2.85 
@, 2.20 
@ 1.46 

@ 1.3U 
@ 1.32 
@ 1.61 
@ 1.46 
@ 1.28 
@ 1.301 
@ 1.26f 
@ 1.76i 
@ 1.14 
® 1.331 
@ 1.32 
@ 1.43i 
@ 1.40 
® 1.13^ 
@ .96 



.9lf 

.84f 
.94f 



@2.00 
@ l.OSf 
@ 1.08i 
@ 1.16 



December 

June 

January 

November 

May 

July 

August 

July 

Feb. , April, and Sept. 

August 

July 

April 

August 

December 

May 

April 

December 

January 

October 

April and May 

June 

February 

April 

January 

June 

September ^ 

February 

August 

April 



iNo. 2 cash wheat. 
2 The Hutchinson " 
ing day. 



corner" figures $1.04^ ©1.05? the follow- 



422 



Appendix 



PRICES OF WHEAT (CHICAGO MARKET) 1863-1910 
{Continued) 



Years 



1892 
1893 
1894 
1895 
1896 
1897 
1898 
1899 
1900 
1901 
1902 
1903 
1904 
1905 
1906 
1907 
1908 
1909 
1910 



Months op Lowest 
Prices 



October . 
July . . 
September 
January . 
June . 
April . . 
October . 
December 
January . 
July . . 
October . 
March . 
January . 
August . 
Aug.-Sept. 
January . 
July . 
August . 
November 



Yearly Range 
OF Prices 



.691 

•54| 

.50 

.48f 

.531 

.64i 

.62 

.64 

.61^ 

.631 

.67^ 

.70i 

.8U 

.771 

.691 

.71 

.84i 

.99i 

.901 



@ 



9lf 
,88 
65i 
@ .83f 
® .941 
@ 1.09 
@ 1.85 
® .79^ 
@ .87i 
@ .79i 
@ .95 
@ .93 
©1.22 
©1.24 
© .94f 
© 1.05i 
© 1.11 
©1.60 
© 1.27i 



Months of Highest 
Prices 



February 

April 

April 

May 

November 

December 

May 1 

May 

June 

December 

September 

September 

October 

February 

April 

October 

May 

June 

February 



' The Leiter " corner" figure. The above table was compiled 
by Charles B. Murray, editor of the Cincinnati Price Current. 



Appendix 



423 



APPENDIX L 
CROP STATISTICS FOR CONTINENTAL UNITED STATES ^ 





Corn 


Wheat 


Oats 


Barley 


Rye 


Average Num- 












ber of Acres 












1867-1876 . 


38,688,449 


21,690,478 


10,195,566 


1,323,839 


1,338,763 


1877-1886 . 


63,408,900 


35,062,189 


17,826,840 


2,153,883 


1,936,360 


1887-1896 . 


74,290,879 


36,583,809 


26,919,954 


3,164,889 


2,077,653 


1897-1906 . 


87,971,235 


45,540,593 


27,689,458 


4,158,986 


1,799,512 


Average Pro- 












duction 












1867-1876 . 


1,011,535,800 


258,407,900 


278,267,071 


29,735,169 


18,217,420 


1877-1886 . 


1,575,626,651 


436,726,976 


491,482,427 


48,137,782 


24,880,175 


1887-1896 . 


1,800,271,093 


464,093,443 


1 686,859,971 


72,117,116 


26,784,385 


1897-1906 . 


2,240,363,473 


631,181,626 


835,644,006 


108,684,958 


28,341,965 


Average Yield 


Bushels 


Bushels 


Bushels 


Bushels 


Bushels 


Per Acre 












1867-1876 . 


26.2 


12.0 


27.5 


22.8 


13.6 


1877-1886 . 


25.1 


12.5 


27.8 


22.4 


13.0 


1887-1896 . 


24.0 


12.7 


25.5 


22.7 


12.9 


1897-1906 . 


25.4 


13.8 


30.1 


25.5 


15.7 


Average Total 












Value 












1867-1876 . 


$457,000,523 


$202,245,463 


$103,401,326 


$23,030,837 


$14,094,508 


1877-1886 . 


625,623,878 


388,867,604 


157,859,103 


28,842,694 


15,454,005 


1887-1896 . 


633,694,378 


319,632,591 


193,005,251 


33,305,476 


14,487,116 


1897-1906 . 


869,575,310 


431,717,233 


246,936,311 


46,158,110 


15,444,264 


Average 


Per Bushel 


Per Bushel 


Per Bushel 


Per Bushel 


Per Bushel 


Value 


Cents 


Cents 


Cents 


Cents 


Cents 


1867-1876 . 


46.5 


103.0 


37.5 


78.3 


76.0 


1877-1886 . 


40.3 


89.8 


32.5 


60.9 


62.8 


1887-1896 . 


36.6 


68.7 


28.7 


46.6 


53.6 


1897-1906 . 


39.0 


6S.8 


29.4 


42.1 


54.3 



1 Calculajted from Yearbook United States Department of 
Agriculture. The average yields per acre and value per bushel 
as here calculated are the averages of the ten yearly averages. 



424 



Appendix 



APPENDIX M 

PLOWING AS AFFECTED BY SHAPE OF THE FIELD 
(8 inch furrow) 



Land 


Length of 
Lands 
(Yards) 


Breadth to 

GIVE AN 

Acre 
(Feet) 


Number of 

Furrows in 

AN Acre 


Time Taken 

TO Turn at 

Ends 


Time Taken 

to Turn 

Soil 










H. M. 


H. M. 


1 


78 


186 


279 


4 39 


3 21 


2 


149 


98 


147 


2 27 


5 33 


3 


200 


73 


109 


1 49 


6 11 


4 


212 


69 


103 


1 43 


6 17 


5 


274 


53 


79 


1 19 


6 41 



Appendix 



425 



APPENDIX N 

AVERAGE DEPRECIATION A YEAR AND COST TO THE 
ACRE FOR FARM MACHINERY (Minnesota Bui. 117) 



Machine 



Depreciation per 

Year, on Original 

Cost 



Cost per Acre 



Threshing outfit . . 
Hay loaders . . . 
Manure spreader . . 
Corn binders . . . 
Harrows .... 

Reapers 

Grain binders . . . 

Mowers 

Hay rakes .... 
Gasoline engines . . 
Corn cultivators . . 
Corn planters . . . 
Grain drills and seeders 
Harness (heavy) . . 

r Sulky . . . 
Plows < Gang . . . 

i Walking . . 
Hay racks .... 

Sleds 

Wagons 

Horse weeders . . . 

Disks 

Hay tedders . . . 
Fanning mills . . . 
Grain tanks . . . 



1.335 
.151 

.826 
.017 
.171 
.181 
.206 
.085 

.155 
.087 
.075 



.087 



.034 for grain 
.158 for corn 
.059 for hay 

.089 
.113 
.010 
.011 



426 Appendix 

APPENDIX 

GLOSSARY 

Alkaloid. — Substances in plants tliat stimulate or deaden nervous 
action, such as strychnine, morphine, and cafFein. 

Ash. — Mineral matter left after biu-ning ; ashes. 

Awns. — Beards on seed-coats or on chaff. 

Bacteria. — Extremely small one-celled plants, — the smallest mem- 
bers of the plant kingdom. They depend on other plants or 
animals, either living or dead, for food. 

Bast. — The fibrous part of the bark. 

Bracts. — Leaflets near the base of true leaf, or on rootstocks ; any 
leaves normally much reduced in size. 

Calyx. — Outer envelope of the flower ; if the parts are separate, 
they are called sepals ; if not wholly separate, they are lobes. 

Cambium. — Growing tissue usually between bark and wood. It 
lies between the phloem and the xylem of the fibrovascular 
bundle, and as these bundles, when active, are on the outside 
of the woody cylinder, the cambium seems to lie between the 
wood and bark. 

Capillary water. — All water that is held in films and that will evapo- 
rate without heating, if exposed to the air. 

Carbohydrates. — Substances consisting wholly of carbon, hydrogen, 
and ox>'gen, such as sugar, starch, and cellulose. They consti- 
tute the greater part of the dry w'eight of plants. 

Cell, —r Smallest unit of living things, consisting of cell-wall in- 
closing jelly-like cytoplasm and heavier nucleus. 

Cellidose. — Material composing cell-walls. Cotton, wood, walnut 
shell, bark, straw, and cabbage leaves are chiefly cellulose. 

Chlorophyll. — Green coloring matter of plants, by the use of which 
plants manufacture their food. 

Corolla. — The petals, or the inner floral envelope, in the flower 
(usually showy). 

Cortex. — The bark. All of the tissues between the cambium and 
the epidermis ; in woody plants, the whole exterior covering of 
the trunk or branches. 

Cortical. — Pertaining to cortex ; outer layers of the potato tuber, 
except epidermis, outside of the faint yellowish-green ring. 

Cross-fertilization. — Fertilization is caused by the male element of 



Appendix 427 

pollen uniting with the female element of the ovule. The 
transfer of pollen from another plant is called cross-pollination. 

Crude fiber. — Fibrous part of plants hard to digest ; cellulose. 

Current meter. — An apparatus lowered into a stream to find how 
fast the water flows. 

Denitrification. — Changing of nitrates to a less usable form of nitro- 
gen. 

Dicotyledons. — Plants with two cotyledons or seed-leaves or with 
seeds in two parts. These plants grow from a cambium and 
lay down rings in the stem. They form two of three great divi- 
sions in higher plants. They are subdivided into gymnosperms 
such as pines, and angiosperms such as oak trees, peas, and all 
plants with split seeds. See Monocotyledons. 

Elements. — Various chemical substances that cannot be separated 
by present means into two or more other substances. 

Embryo. — The part of the seed that begins growth ; the germ. 

Endodermis. — Inner skin, usually rich in starch. 

Endosperm. — The contents of a seed that lies outside the germ or 
embryo. It supplies food for the growing seedling. It is the 
white part of wheat. 

Entomology. — The science that deals with insects. 

Enzymes. — Chemical substances within plants or animals that aid in 
reactions or changes, such as the transformation of starch to sugar. 

Epidermis. — An outer covering (from epi, outside, and dermis, skin) ; 
it is cast off by trees in early years of growth. The outer cover- 
ing of trees is often cortex. 

Fermentation. — The breaking down or changing of compounds by 
chemical reaction, such as the heating of manure and the 
formation of alcohol from sugar by yeast. 

Fibro-vascular bundle. — Bundle or body consisting of fibers, and of 
ducts which transport . water up the stems and elaborated 
foods down the stem. They show in corn pith as strands, and 
in wood and squash vines as V-shaped bundles. 

Flocculation. — Grouping of the soil particles. 

Formalin. — Solution of formaldehyde in water, usually 40 per cent. 

Fungus, fungi. — A group of plants such as mildew, smut, mold, and 
muslirooms consisting mostly of thread-like tissues and devoid 
of chlorophyll. They propagate by means of spores (detached 
cells) instead of seeds. 

Genus. — A group of closely-related species of plants, all bearing one 
general name, as Trifolium, the clovers ; Populus, the poplars. 



428 Appendix 

Gravitational water. — Water in excess of film water. It passes down- 
ward through soil due to pull of gravity. 

Hygroscopic water. — Water held closely by soil particles as a thin 
film. It cannot be evaporated without heating. 

Lenticels. — Pores in plants. The epidermis is often torn by the 
growth beneath. These openings may penetrate into deep tissue. 

Ldnt. — Cotton fiber. 

Linters. — Short fiber on cotton seed. 

Medullary. — The inner layers of the potato, inside the faint yellow- 
ish-green ring. 

Medullary rays. — Ducts or pithy areas extending radially from 
bark to center of stem. 

Microorganisms. — Plants or animals so small that they cannot be 
seen without a microscope. 

Monocotyledons. — Plants having only one cotyledon or seed-leaf, or 
seed in one part. They usually have parallel-veined leaves, 
and since they have no cambium, do not lay down rings in 
growth. They constitute one of three great divisions of higher 
plants. All grasses and cereal grains, palms, lilies, and orchids 
are examples. See Dicotyledons. 

Natural selection. — Selection or persistence in nature of those in- 
dividuals most fit to survive, out of the many that begin life. 

Nitrification. — Changing less available nitrogen to nitrates which 
are readily used by plants. Bacteria change ammonia, free 
nitrogen, and nitrites to nitrates by oxidizing them. 

Nitrogen-fixation. — Making free nitrogen into compounds of nitro- 
gen that are solids or can be made into solids readily. 

Nodules. — Enlargements on roots of legumes containing colonies 
of bacteria which live on food made by the plant, but which 
take nitrogen from the air. Legumes are the only agricultural 
plants known to bear nodules. 

Nucleus. — The center of cell activity, usually darker than the 
other cell contents. 

Organism. — Any living thing or body, as a plant, an animal, a mi- 
crobe. 

Osmosis. — Passage of water or dissolved material through a mem- 
brane to equalize the concentration of the solution on both 
sides of the membrane. 

Ovary. — The part of the pistil containing the ovule or ovules ; the 
seed-case. 

Ovule. — The body which, after fertilization, becomes the seed. 



Appendix 429 

Palisade cells. — Elongated cells under the epidermis of some leaves. 

Panicle. — Branching flower-cluster or seed-cluster, as in oats. 

Parasites. — Plants or animals that subsist or feed on living plants 
or animals. 

Pathology. — The science concerned with the nature, cause, and con- 
trol of disease. 

Pericycle. — Region of the stem just outside the phloem ; inner bark. 

Phloem. — Fibrous tissue on the inner part of the bark just outside 
the cambium tlirough which elaborated plant-food passes 
downward. 

Photosynthesis. — Manufacture of sugar and starchy foods by 
chlorophyll in the presence of sunlight from water and carbon 
dioxide. (From photo, light, and synthesis, to put together.) 

Pistil. — Ovule-bearing organ of flowers, consisting of ovary, style, 
and stigma ; when ripe or mature, the seed-case. 

Plasma membrane. — A thin, colorless membrane covering the pro- 
toplasm. 

Plastids. — Small distinct bodies of protoplasm, which store starch 
and which contain chlorophyll or the yellow color of flowers. 

Pollen. — Contents of the an-thers, usually in the form of small grains. 
Pollen carries within it the male element. When this unites 
with the female element in the ovule, fertilization results and 
seed growth begins. Pollen is usually fine powder, such as the 
yellowish dust that comes from corn tassels. 

Protein. — Plant or animal compounds comprising protoplasm, con- 
taining nitrogen and sulfur, in addition to carbon, hydrogen, 
and oxygen. 

Protoplasm. — The living contents of a cell, rich in nitrogen. 

Reproduction. — Process of starting the next generation. 

Respiration. — Breathing ; a process that proceeds in all living or- 
ganisms. Oxygen is used up, carbon dioxide liberated, and heat 
given off. 

Saprophytes. — Organisms that secure a part of their food for energy 
from foods already combined. These foods are often dead 
tissue. 

Self-fertilization. — Fertilization results from a union of pollen and 
ovule. When pollen fertilizes the ovule of the same plant, the 
process is called self-fertilization. See Cross-fertilization. 

Sieve-tubes. — Vertical row of cells in the phloem through which 
elaborated food passes downward, so-called because of sieve- 
like end walls. 



430 Appendix 

Species. — One kind of plant, as alfalfa, red clover, white clover, 

sugar maple, oat. Any group or assemblage of individuals 

that are so much alike as to seem to l)e the progeny of one similar 

ancestor, or which are not sufficiently unlike to warrant the 

giving of more than one botanical name to them. 
Spermatophytcs. — Plants that produce seeds, as all the so-called 

higher plants. 
Spike. — Cluster when seeds or flowers are borne on short pedicels 

or branches bringing the spikelets close together, as in wheat. 
Sponge tissue. — Loose tissue in leaf, so-called because of large 

spaces between cells. 
Stamens. — The pollen-bearing organs of flowers ; the essential part 

is the anther or pollen-case, and this is usually borne on a stalk 

or filament. 
Stigma. — The part of the pistil that receives the pollen ; it is usually 

at the top of a style or stalk. 
Stoloniferous. — Spreading by means of rooting branches, or stolons 

which appear at or near the surface ; in grasses, sod-forming by 

rootstocks. 
Stomata. — Mouth-like openings in leaves of plants. They permit 

the intake of carbon tlioxide and allow water and oxygen to 

pass out. When plants wilt, two small cells fall together, partly 

closing the opening. 
Style. — The neck-like or stalk-like part of the pistil that holds the 

stigma well out toward the opening of the flower. 
Tissue. — Groups of cells that do the same kind of work ; specialized 

parts of plants or animals. 
Tracheal tubes. — Channels or tubes in woody part of plant, for carry- 
ing water from roots to leaves. They are found in the xylem 

and have thick and thin places in their walls. 
Translocation. — Movement of stored food from one part of the plant 

to another. 
Transpiration. — ■ The giving off of water from the leaves and other 

parts of plants. This Avater has been used in carrying dissolved 

material to the leaves Evaporation also cools the leaves 

in hot weather. 
Vacuoles. — ■ Bodies of cell-sap inclosed in the cyptoplasm. 
Weir. — A device to measure flowing water. 
Xylem. — That part of the fibro-vascular bundle, tlu-ough which 

sap passes upward. It lies within the cambium. Wood in 

trees is almost entirely xylem. 



INDEX 



Absorption, selective, 46. 
Accounts, farm, 403. 
Acid or sour soils : 

cause of, 157. 

correction of, 157. 

how detected, 157. 
Acre-foot defined, 103. 
Action of enzymes, 43, 60. 
Adaptability of crops, 12, 21. 
Adaptation of : 

alfalfa, 262, 390. 

barley, 216, 3S9. 

beans, 278. 

beets, 243. 

brome-grass, smooth, 297. 

corn, 198, 389. 

cotton, 335, 390. 

cowpeas, 281. 

crops, 12, 21, 387. 

field-peas, 276. 

flax, 337. 

hemp, 240. 

Kentucky blue-grass, 294. 

mangels, 390. 

oats, 210, 389. 

orchard-grass, 295. 

plants to environment, 12, 21, 48, 
149. 

potatoes, 228, 390. 

red clover, 273. 

redtop, 293. 

rice, 221, 390. 

rye, 220, 390. 

sorghum, 323. 

soybeans, 283. 

sugar-beets, 243, 390. 

sugar-cane, 390. 

tobacco, 345. 

timothy, 289. 

vetch, 284. 

wheat, 173, 390. 



Advantages of furrow irrigation, 103. 
Aeration of the soil, factors influenc- 
ing, 86. 
Age of plants and usefulness, 61. 
Agents of soil formation, 74. 
Agriculture : 

and the advance of civilization, 3. 

and the sciences, 2. 

as a business, 2. 

as an art, 1. 

as a science, 1. 

definition of, 1. 

divisions of, 4. 

its scope, 1. 

opportunities in, 3. 

relation to other professions and 
industries, 1, 3. 

social and educational aspects of, 
3. 
Agronomy : 

definition of, 4. 

phases of, 4. 
Air: 

distribution through tissues, 41. 

in the soil, importance of, 86. 
Aleurone cells in wheat kernel, 171. 
Alfalfa, 256. 

adaptation, 262. 

and permanent agriculture, 256. 

common, 261. 

cultivation, 263. 

distribution, 262. 

enemies, 267. 

flower, 260. 

Grimm, 261. 

harvesting, 264, 269. 

history, 257. 

inoculation, 262. 

irrigation, 264. 

leaf-wee\'il, 269, 370. 

leaves. 260. 

marketing. 266. 

mixtures, 276. 



431 



432 



Index 



Alfalfa: 

name, 256. 

nodules, 259. 

nurse crops, 263. 

pasture, 267, 304. 

planting, 263. 

relationships, 258. 

root-system, 258. 

seed, 260. 

seed-bed preparation, 263. 

seed production, 269. 

Siberian, 261. 

stems, description, 259. 

storage, 265. 

value, 266. 

varieties, 261. 

weeds, 267. 
Alkali : 

injury done to vegetation, 156. 

injury to plants, 46. 

kinds of, 155. 

permanent freedom from, 108, 
156. 

reclamation of, 156. 

resistance of sugar-beets, 245. 

some of its problems, 154. 
Alsike clover, 274. 
Aluminum minerals, 71, 72. 
Amendments, 126. 
Analysis of soils, 120. 

how useful, 127. 

in land valuation, 163. 
Animal : 

fiber, 333. 

husbandry, its field, 4. 

pathology, 4. 
Animals: 

as agents in soil formation, 79. 

dependence on plants, 51. 
Apatite, composition, 73. 
Aphis, cabbage, 344. 
Apparent and real specific gravity 

compared, 86. 
Apples, 349. 
Arid and humid soils compared, 81, 

120. 
Ash: 

amount in plants, 56. 

uses by plants and animals, 56. 
Astragalus, 284. 
Atmosphere in soil formation, 78. 



Bacteria, 139. 

action on organic matter, 141. 

and soil nitrogen, 142. 

classes of, 139. 

description, 139, 140. 

food and growth, 140. 

how the farmer may assist, 144. 

number of, in soils, 139. 
Barley, 215. 

adaptation, 216. 

alkali resistance, 216. 

cultivation, 217. 

description, 215. 

distribution, 216. 

enemies, 218. 

harvesting, 217. 

history, 215. 

marketing, 218. 

pests, 218. 

seeding, 217. 

standard varieties, 216. 

uses, 219. 

value, 219. 
Basalt, 71. 
Beans, 278, 349. 

culture, 278. 

description, 278. 

harvesting, 280. 

planting, 279. 

use, 280. 
Beetles, flea, 344. 
Beets, 251. 

culture and good farming, 250. 

relationships, 241. 

sugar, 251. 
Benefits : 

of drainage, 108. 

of manure, 132. 

of organic matter, 88. 
Bermuda-grass, 299. 
Berseem, 275. 
Bindweeds, 358. 
Bird's-foot trefoil, 284. 
Blackleg of potato, 238. 
Blade of grass leaf, 170. 
Blight, early, 237. 
Blowing of soils, treatment for, 159, 

160. 
Blue-grass, Kentucky, 304, 393, 



Index 



433 



Bordeaux mixture, 237. 
Branches, 37. 

Bread and wheat quality, 182. 
Breeding : 

of plants, 356. 

plats, 361. 

steps in, 362. 
Broom-corn millet, 331. 
Bryophytes or mosses, 26. 
Buckwheat, 222. 
Buds, 37. 
Buildings : 

arrangement of, 398. 

convenience and sanitation, 398. 

cost of, 398. 

farm, 398. 
Bur clovers, 275. 



Cabbage, 342. 

curculios, 344. 

enemies of, 343. 

looper, 344. 

root maggot, 344. 
Cacti, 351. 
Calcite, composition and importance 

of, 72. 
Calcium, 43. 

Calcium carbonate, 72, 73. 
Calcium-loving crops, 117, 136. 
Calyx, 35. 
Cambium, 32. 

Canada blue-grass, 293, 304. • 
Canada thistle, 358. 
Cane-sugar, manufacture of, 347. 
Cantaloupes, 349, 364. 
Capillary water : 

amount held, and texture, 92, 93. 

importance, 92. 

movement, 92. 
Capital on farm, 401. 
Carbohydrates : 

amount in plants, 55. 

composition, 55. 

forms found in plants, 55, 60. 

uses to animals, 55, 56. 
Carbolic acid for spray, 376. 
Carbon bisulfide, 344. 
Carbon dioxide : 

in mineral solution, 72, 76, 78. 
2f 



Carbon dioxide: 

source of fuel, 52. 

use by plants, 42, 43, 57. 
Care of machinery, 397. 
Carnations, rust-resistant, 362. 
Carrots : 

culture, 255. 

description, 254. 

use, 255. 
Cauliflowers, 349. 
Cells, 23, 42. 

activities within, 42. 

division, 40. 

specialization, 26. 

structure of, 24, 25. 
Cellulose, formation by plants, 43. 
Cereals : 

their relationship, 168. 

value of, compared, 184, 219. 
Chalcis fly, 268. 
Chemical analysis of soil in land 

valuation, 1G2. 
Chemistry, field of, 4. 
Cherries, 349, 388. 
Chess, 297. 
Chickpeas, 284. 

Chinch-bugs, injury to wheat, 180. 
Chlorite, composition and impor- 
tance, 72. 
Chlorophyll, 42. 

dependence of life upon, 59. 
Citrus-fruits, 349. 
Civilization, relation to agriculture, 

■ 3. 
Classes of bacteria, 139. 
Classes of farm implements, 150. 
Classification of soils, 79. 
Clay, sources of, 71. 
Cleavage and decomposition of rock, 

71. 
Climate and wheat quality, 183. 
Clover : 

alsike, 274. 

as a cover crop, 349. 

bur, 275. 

crimson, 275. 

for pasture, 304. 

Persian, 275. 

"sickness," 271. 

sweet, 181, 274. 

white, 274. 



434 



Index 



Clovers and other legumes, 254, 271. 
Cocaine, 344. 
Cocklebur, 375. 
Coffee, 351. 
Composition of : 

carbohydrates, 55. 

fats and oils, 56. 

feldspars, 71. 

gypsum, 73. 

hornblende, 71. 

mica, 71. 

plants, 61, 122. 

protein, 56. 

pyroxene, 71. 

soils, 67, 70, 81, 119. 
Conservation of soil, 68. 
Control of : 

June-grass, 297. 

moisture, 10, 18, 100-117. 

mustard, 181. 

plant-food, 10. 

plant composition and yield, 62. 
Cork cells, 29, 32. 
Corn, 191. 

adaptation, 198. 

culms, 193. 

cultivation, 201. 

dent, 195. 

distribution, 197. 

ear, 194. 

enemies, 204. 

factors in production, 198, 199. 

flint, 196. 

flower, 194. 

harvesting, 203. 

history of, 191. 

irrigation of, 202. 

kernel described, 194. 

leaves, 193. 

marketing, 206. 

pests, 204. 

pod, 197. 

pop, 196. 

relationships, 191. 

root-system, 191. 

seed and planting, 200. 

seed-bed preparation, 199. 

seed, selection of, 200. 

silage, 203. 

soft or flour, 197. 

standard varieties, 197. 



Corn: 

states producing, 197. 

storage, 205. 

sweet, 196. 

types, 195. 

uses, 204. 

value, 205. 

with cowpeas and rape, 203. 
Corolla, 36. 

Corrosive sublimate for spray, 377. 
Cortex, 29. 

Cost of buildings, 398. 
Cost of drainage, 109. 
Cotton, 333. 

adaptation of, 335. 

culture, 336. 

description of, 335. 

distribution, 336. 

harvesting, 337. 

history, 333. 

marketing, 337. 

use of, 337. 

varieties, 334. 
Cowpeas, 280. 

adaptation, 281. 

ctilture and value, 282. 

description, 280. 

with corn, 203. 
Crimson clover, 275. 
Critical periods of plants for water, 

105. 
Critical points in soil moisture, 

93. 
Crop production limited by elements, 

122. 
Crops : 

adaptation of, 12, 21, 387. 

adapted to dry-farming, 115. 

as income, 387. 

diversified, 388. 

knowledge of, 404. 

miscellaneous, 341. 

relation to soil texture, 82. 

staple, 382. 

storage of, 405. 
Cross-fertilization, 362. 
Crystalline rock, 71. 
Cucumbers, 349. 
Culms : 

of corn, 193. 

of wheat, described, 170. 



Index 



435 



Cultivation : 

and manuring, objects of, 20, 146, 
148, 149. 

and moisture in soil, 146, 149. 

benefits derived from, 145. 

improvement of soil structure bj', 
145. 
Cultivators, Icinds of, 151. 
Culture of : 

alfalfa, 263. 

barley, 217. 

beans, 278. 

beets, 245. 

brome-grass, smooth, 297. 

clover, 255. 

corn, 201. 

cotton, 336. 

cowpeas, 282. 

field-peas, 277. 

flax, 338. 

hemp, 341. 

mangels, 252. 

millets, 330. 

oats, 212. 

orchard-grass, 295, 296. 

potatoes, 224, 234. 

red clover, 273. 

redtop, 293. 

rice, 221. 

rutabagas, 254. 

rye, 220. 

sorghum, 325. 

soybeans, 283. 

Sudan-grass, 329. 

sugar-beets, 245, 247. 

timothy, 289. 

tobacco, 346. 

turnips, 253. 

wheat, 175-178. 
Curculios, cabbage, 344. 
Cytoplasm, 25. 

D 

Dandelions, 374. 

Decomposition of organic matter, 

141, 153. 
Definition of mineral, 70. 
Denitrification, 144. 
Dent corn, 196. 
Dependence of man on plants and 

animals, 51, 53, 58. 



Depreciation in machinery, 396. 
Depth of drains, 110. 
Depth of soils, 81. 
Description of : 
alfalfa, 258. 

flower, 260. 

leaves, 260. 

roots, 258. 

seeds, 260. 

stems, 259. 
barley, 215. 
beans, 278. 

Canada blue-grass, 293. 
carrots, 254. 
clover, 271. 

alsike, 274. 

crimson, 275. 

red, 272. 

sweet, 274. 

white, 274. 
corn, 

culms, 193. 

ear, 194. 

flower, 194. 

kernel, 194. 

leaves, 193. 

roots, 191. 
cotton, 335. 
cowpeas, 280. 
field-peas, 275. 
flax, 338. 
grass, 287. 

Kentucky blue-grass, 293. 
leaf, 34. 

mangel-wurzels, 251. 
mUlet, 330. 
oats, 209. 
orchard-grass, 295. 
potatoes, 225 
red clover, 272. 
redtop, 292. 
rice, 221. 
rutabagas, 253. 
rye, 219. 

smooth brome-grass, 297. 
sorghum, 320. 
soybeans, 282. 
sugar-beets, 243. 
timothy, 288. 
turnips, 253. 
vetch, 284. 



436 



Index 



Description of: 

wheat, 

culm, 170. 
kernel, 170. 
root, 168. 
Diabase, 71. 

Diamond-back moths, 344. 
Dicotyledonous plants, .35, 40. 
Diffusion of salts, 45. 
Diorite, 71. 

Disease prevention, Bordeaux mix- 
ture, 337. 
Diseases of : 

alfalfa, 267. 

barley, 218. 

beets, 248. 

corn, 204. 

potatoes, 236, 238. 

sugar-beets, 248. 

wheat, 176, 179, 180, 181. 
Distribution of : 

alfalfa, 262. 

barley, 216. 

beans, 278. 

beets, 245. 

blue-grass, 294. 

brome-grass, 394. 

buckwheat, 222. 

corn, 197, 198. 

cotton, 335, 336. 

cowpeas, 281. 

mangels, 252. 

millet, 329, 330. 

native grass, 304. 

oats, 210, 211. 

orchard-grass, 295. 

potatoes, 228. 

red clover, 272. 

redtop, 293. 

rice, 221. 

rye, 219, 220. 

sorghum, 323. 

Sudan-grass, 329. 

sugar-cane, 347. 

sweet clover, 275. 

sweet potatoes, 347. 

timothy, 289. 

tobacco, 345. 

wheat, 173. 

white clover, 274. 
Diversification of crops, 383, 388. 



Diversity of crops, advantage of 

under irrigation, 106. 
Division of cells, 40. 
Dolomite, composition and impor- 
tance, 71. 
Domestication of plants and animals, 

53, 54. 
Drainage : 

and the alkali problem, 108, 
156. 

Ijenefits of, 108. 

cost of, 109. 

reduces heaving, 109. 

scope of problem, 109. 
Drains : 

covered, 110. 

depth to lay, 110. 

open ditches, advantages and dis- 
advantages, 110. 

procedure in installing, 110. 
Drouth-resistant plants, 16, 21. 
Dry-farm : 

areas of the U. S., 112. 

crops, 115. 

machinery for, 117. 

tillage methods, 116. 
Dry-farming : 

in relation to rainfall, 111. 

scope of problem. 111. 

soils suited to, 113. 

sorghums for, 319. 

tillage in, 116. 
Dry matter, cost of, 47. 
Dry-rot of potatoes, 238. 
Duty of machinery, 395. 
Dye plants, 351. 



E 



Ear of corn described, 194. 

Early blight, 237. 

Effect of manure on plants, 131. 

Effect of water on development of 

plants, 10. 
Elements limiting crop production, 

122. 
Elevation and temperature, 16. 
Elevators, grain, 136. 
Embryo of wheat kernel described, 

' 171. 
Embryo or germ, 37. 



Index 



437 



Emmer, 222. 
Endodermis, 29, 32. 
Enemies : 

of cabbage, rape, and kale, 343. 

of corn, 204. 

of oats, 214. 
Entomology, 4. 
Environment : 

adaptation of plants to, 12, 21, 48, 
149. 

and native vegetation, 9. 

modifications by man, 9. 

relation of plants to, 9. 

response of plants to, 4. 
Enzymes, action of, 43, 60. 
Epidermis, 25. 
Equipment, necessary, 393. 
Erosion : 

conditions where troublesome, 158. 

factors affecting, 158. 

methods of preventing, 158. 
Evaporation from soils, prevention 

of, 95. 
Executive ability of farmer, 403. 
Exhaustion of soils by removal of 

plant-food, 123. 
Existence, struggle for, 50. 



Factors in crop production, 12, 

20. 
Factors of plant growth and their 

control, 10. 
Families of plants, 26. 
Farm: 

accounts, 403. 

buildings, 398. 

good roads on, 384. 

planning, 381. 

size of, 400. 
Farmer, executive ability, 400. 
Farmer's income, 403. 
Farming : 

machinery for, 392. 

management of, 402. 

organization of, 400. 

persistence needed in, 382. 

rearranging, 384. 

relation of sugar-beets to, 250. 

types of, 402. 



Farm manure : 

losses in, 133. 

value of, 126, 131. 
Farmstead, 383. 

convenience in arrangement of, 
383. 

location of, 383. 
Fats and oils : 

composition, 56. 

occurrence, 56. 

uses, 57. 
Feldspars, composition and impor- 
tance, 71. 
Fences : 

neat, 385. 

unnecessary, 385. 
Fenu-greek, 284. 
Ferns, 26. 

Fertility of soil, importance of con- 
servation, 68. 
Fertilization, 259. 
Fertilization of corn, 194. 
Fertilizers : 

advantages of home-mixing, 130. 

commonly used, 126. 

indirect, 126. 

judgment needed in applying, 
127. 

needed by different crops, 136. 

phosphorus, 128. 

potassium, 129. 

used as stimulants, 130. 

used for nitrogen, 127, 128. 

value used in U. S., 126. 

waste of, 126. 
Fescues, 301. 
Field-peas, 275. 

adaptation, 276. 

culture, 277. 

description, 275. 

harvesting, 277. 

irrigation, 277. 

seeding, 276. 

use and value, 277. 
Fields, size and shape of, 384. 
Fiber : 

animal, 333. 

miscellaneous, 341. 

vegetable, 333. 
Fibro-vascular bundles, 32. 
Fixation of nitrogen, 128, 142. 



438 



Index 



Flax : 

adaptation, 338. 

culture, 338. 

description, 338. 

fiber, 339. 

history of, 338. 

seed, 339. 

use of, 340. 

value of, 340. 
Flea-beetles, 344. 

on beets, 249. 
Flint, 71. 
Flint corn, 196. 
Florida beggar weed, 284. 
Flour quality, 182. 
Flower : 

described, 36. 

parts of, 359. 
Fluctuations in yield due to climate, 

13. 
Food : 

of bacteria, 140. 

reserve in plants and animals, 59, 
60. 

storage by plants, 185. 

storage in seed, 60. 
Forage crops compared, 291. 
Forage grasses, 288. 
Forces in transference of food, 49. 
Formalin for seed diseases, 238. 
Formation of cellulose by plants, 43. 
Formation of humus, 141. 
Former plants, products of, 52. 
Foxtail, 367. 
Frost : 

crops hardy toward, 13. 

effect on some common crops, 13, 
14. 

factors influencing, 14. 

injury to crops, nature of, 14. 

time of, 14. 
Fruits, 349. 

sitrus, 349. 

small, 349. 

tropical, 351. 
Function of plant parts, 27. 
Functions, specialization of, 39. 
Furrow irrigation, advantages of, 

103. 
Fusarium oxysporum, 238. 
Fusarium wilt, 238. 



G 



Gardens, roof, 351. 

Genus, 26. 

Germination and oxygen, 42. 

Glacial soils, 78. 

Glaciers, action in soil formation, 77. 

Gliadin, 182. 

Gluten, 182. 

Glutenin, 182. 

Gneisses, 71, 72. 

Grades of wheat, 188. 

Grain : 

drilling, 396. 

handling on a large scale, 186. 

loss in storage, 189. 

speculation, 189. 
Gramineaj, plants included under, 168. 
Granite, 70, 73. 
Grapes, seedless, 364. 
Grass, Bermuda, 299. 

blade of, 170. 

leaf sheath of, 170. 
Grasses, 286. 

description, 287. 

forage, 288. 

importance of, 287. 

mixtures for pasture, 305. 

native, 304. 

relationships, 286. 
Grasspeas, 284. 
Gravitational water, its importance, 

91, 92. 
Greenhouses, 351. 
Green manure, 136. 
Grimm alfalfa, 261. 
Growth in higher plants, 39, 40. 
Guar, 284. 

Gypsum, composition and impor- 
tance, 73. 



H 



Handling manure, 134. 
Hard wheat regions, 172. 
Harvest control by crop and ma- 
chinery, 62. 
Harvesting of : 

alfalfa, 264, 269. 

barley, 217. 

beans, 280. 



Index 



439 



Harvesting of: 

beets, 250. 

brome-grass, smooth, 298. 

corn, 203. 

cotton, 337. 

field-peas, 277. 

mangels, 252. 

oats, 213. 

orchard-grass, 295. 

potatoes, 235. 

red clover, 273. 

rice, 221. 

soybeans, 283. 

sugar-beets, 347, 349. 

timothy, 290. 

wheat, 178, 189. 
Hay, oat, 208. 
Heart-rot of beets, 248. 
Heat and cold as agents in soil for- 
mation, 74. 
Heat : 

factors influencing, 87, 88. 

importance of, 87. 

of soils and moisture, 9, 18. 

total, 16. 
Heaving of soil reduced by drainage, 

109. 
Hematite, 73. 
Hemlock, 371. 
Hemp, 240. 

adaptation, 240. 

cultivation of, 341. 

Manila, 341. 

New Zealand, 341. 
Herbicides, use of, 376. 
Hessian flies, injury to wheat, 180. 
Home-mixing of fertilizers, 130. 
Hops, 351. 

Hornblende, composition and im- 
portance, 71. 
Hornstone, 71. 
Horticulture, its field, 4. 
House-gardens, 351. 
Housing machinery, 397. 
Humid and arid soils compared, 120. 
Humus formation, 141. 
Hungarian clover, 275. 
Hyacinth beans, 284. 
Hydrous silicates of magnesia, 72. 

of alumina, 72. 

of lime, 72. 



Hygroscopic water, 93. 
definition, 92. 
importance, 93. 



Ice in soil formation, 77. 
Implements : 

classes on farm, 150. 

to kill weeds, 148. 
Improvement of crops, 353. 

by breeding of plants, 356. 

by cultivation of crops, 357. 

by selection, 361. 

defined, 354. 

gains from, 353. 

ideals of, 356. 

methods of, 353, 357. 

need of, 353. 

pastures, 308. 

seed, clean, 357. 

seed impurities in, 358. 

varieties, adapted, 356. 
Improvement of soil structure, 

145. 
Income, Farmers', 403. 
Income from crops, 387. 
Increase in size of plants, means of, 

40. 
Indicators of soil acidity, 157. 
Indirect fertilizers, 126, 130. 
Injury : 

by alkali, nature of 46, 156. 

of frost, 14. 

to wheat by chinch-bug, 180. 
Inoculation for alfalfa, 262. 
Insect pests of : 

alfalfa, 267. 

barley, 218. 

beets, 249. 

cabbage, 344. 

corn, 204. 

oats, 214. 

potatoes, 236. 

sugar-beets, 249. 

wheat, 180. 
Iron minerals, 71, 72, 73. 
Iron sulfate for spray, 377. 

use by plants, 43. 
Irrigation by flooding, advantages, 
104. 



440 



Index 



Irrigation of : 

alfalfa, 264. 

corn, 202. 

orchard-grass, 349. 

potatoes, 234. 

rice, 221. 

sugar-beets, 247. 
Irrigation water : 

amount to use, 104. 

measurement, 102. 

methods of applying, 103. 

sources of supply, 100. 

storage, advantages of, 101, 102. 

use of too much, 106. 

when to apply, 105. 
Istle, 341. 



Jackbeans, 284. 
Japan clover, 2S4. 
Jasper, 71. 
Jethro Tull, 44. 
Johnson-grass, 300. 
Judging value of land, 161. 
June-grass, 297. 

control of, 181. 
Jute, 341. 

K 

Kale, 343. 

enemies of, 343. 
Kentucky blue-grass, 293, 304. 

adaptation, 294. 

description, 293. 

seeding, 294. 

value and use, 294. 
Kernel of corn described, 194. 
Kinds of cultivators, 151. 
Knowledge of crops, 404. 
Kohlrabi, 342. 
Kudju, 284. 



Labor of man and horse, 403, 404. 
Land : 

effect of vegetation on value of, 161. 

judging value of, 161. 

value in relation to plant-food, 124. 

waste, 386. 
Larkspur, 371. 



Late blight of potatoes, 237. 
Leaf, description of, 34. 
Leaf-spot of beets, 248. 
Leaf-weevil, alfalfa, 269, 371. 
Leaves of corn, 193. 
Legumes, 271-285. 

and nitrogen fixation, 142. 

description, 258. 
Lespedeza or Japan clover, 284. 
Life depends on sunshine, 69. 
Lime : 

as a fertilizer, 129. 

feldspars, 71. 

for soil acidity, 157. 

hydrous silicates of, 72. 

sulfate of, 73. 
Limestone, 72. 

dissolved by carbon dioxide, 72. 
Limonite, 73. 
Liquid manure, 133. 
Living, standard of, and wheat, 184. 
Location of farmstead, 383. 
Loco, 371. 

Loopers, cabbage, 344. 
Loss in weight of plants by respira- 
tion, 42. 
Losses in farm manure, 133. 
Lupines, 284. 

M 
Machinery: 

care in selecting, 394. 

care of, 397. 

cooperation, 395. 

depreciation of, 396. 

duty of, 395. 

for dry-farming, 117. 

for farming, 392. 

housing, 397. 

size, 395. 
Maggot, cabbage-root, 344. 
Magnesia minerals, 71, 72. 
Magnesium used by plants, 43. 
Magnetite, 73. 
Maguey, 341. 
Mallow, 374. 
Malt barley, 217. 
Man : 

dependence on plants and animals, 
51, 53, 58. 

to control the earth, 63. 



Index 



441 



Management : 

of farms, 402. 

of meadows, 31 i. 

of pastures, 310. 
Mangel-wurzels, 251. 

culture, 252. 

description, 251. 

harvest, 252. 

use, 252. 
Manila hemp, 341. 
Manufacture of food by plants, 57. 
Manufacture of plant-food, 43. 

of cane-sugar, 347. 
Manure, 132. 

benefits of application, 132. 

effect on plants, 131. 

from different animals, 132. 

green, 136. 

green manuring, best crops for, 13fi. 

handling, 134. 

liquid, 133. 

losses by exposure, 133. 

pile, correct form, 135. 

spreaders, usefulness, 136. 

storage of, 133. 
Maple sugar, 351. 
Marketing of : 

alfalfa, 266. 

barley, 218. 

beets, 250. 

corn, 206. 

cotton, 337. 

potatoes, 235. 

sorghums, 328. 

sugar-beets, 250. 

tobacco, 340. 

wheat, 187, 188. 
Markets : 

knowledge of, 405. 

profitable, 388. 

retail, 405. 

wholesale, 405. 
Meadow-grasses, 301. 
Meadows : 

management of, 31. 

native grass, 304. 

natural, 311. 

rushes, 304. 

sedges, 304. 
Mechanics, The farmer's knowledge 
of, 392. 



Medicinal plants, 351. 

Medullary rays, 32. 

Melons, 249. 

Mendel, Gregor, 363. 

Mendel's law, 363. 

Mexican clover, 275. 

Mica, composition and importance, 

71. 
Milkweed, 358. 
Millet : 

broom-corn, 331. 

culture, 330. 

description, 330. 

importance, 329. 

Japanese barnyard, 331. 

Pearl, 331. 

relationship, 330. 

value, 330. 
Mineral plant-food, 10. 
Minerals : 

definition of, 70. 

in soil and permanent agriculture, 
125. 

in soil, balance of, needed, 125. 

needed by plants, 43. 

soil-forming, 70. 

solution by carbon dioxide, 72, 76, 
78. 
Mixed grass pastures, 304. 
Mixtures of grasses, 305. 
Mixtures with alfalfa, 267. 
Moisture control, 10, 18, 100, 117. 
Moisture in soils : 

action under different conditions, 
91. 

critical points, 93. 

effect of rolling land on, 150. 

forces active in, 96. 

forces influencing movements of, 
96. 

functions performed by, 96. 

naovements of, 96. 

prevention of losses, 94. 

variations in amount, 91. 
Moisture problems in dry-farming, 

111, 112. 
Monocotyledonous plants, 33, 34, 35. 
Morning-glory, 367. 
Mosses, 26. 
Moth beans, 284. 
Moths, diamond-back, 344. 



442 



Index 



Movement of capillary water, 92. 
Movements of soil moisture, 96. 
Mung beans, 284. 
Mustard, 375. 

control of, 181. 

tumbling, 359. 



N 



Native grasses, 304. 
Native grass pastures, 304. 
Natural selection, 359, 3G0. 
Negative factors in crop production, 

12, 20. 
New Zealand hemp, 341. 
Nitrification, 142. 
Nitrogen, 45. 

and wheat quality, 182. 

cycle, 143. 

fertilizers, 127, 128. 

fixation, 128, 142. 

its importance in soils, 122. 

of soil and bacteria, 142. 

restoration by bacteria, 142. 

sources of supply, 127. 
Nodes of grasses, 170. 
Nodules of alfalfa, 259. 
Nucleus, 25. 

Nurse crops for alfalfa, 263. 
Nuts, 351. 



O 



Oat-grass, tall meadow, 29, 304. 
Oats, 208. 

adaptation, 210. 

and peas for forage, 276, 277. 

cultivation, 212. 

description of plant, 209. 

distribution, 210, 211. 

enemies, 214. 

harvesting and storing, 213. 

hay, 208. 

history, 208. 

marketing, 213. 

panicle of oats, 209. 

pests, 214. 

relationships, 209. 

seeding, 212. 

spikelets of oats, 210. 

uses, 213. 



Oats: 

varieties, 212. 

yields by states, 211. 
Occurrence of fats and oils, 56. 
Ochrus, 284. 

Oil formation by plants, 43. 
Opal, 71. 
Opium, 344. 

Opportunities in agriculture, 3. 
Oranges, seedless, 364. 
Orchard-grass, 295-304. 

adaptation, 295. 

description, 295. 

harvesting, 296. 

irrigation, 349. 

seeding, 295. 

value and use, 296. 
Orchard, soils, 349. 

cultivation, 349. 
Organic matter : 

action on soil, 141. 

arid and humid regions compared, 
119. 

beneficial effects on soils, 88. 

decomposition, 141, 143. 

how maintained, 88. 

plant-food content of, 124. 

sources of, 88. 
Organisms of the soil : 

bacteria, 139. 

importance of, 138. 

kinds, 138. 
Organization of farming, 400. 
Origin of branches, 37. 
Origin of buds, 37. 
Orthoclase feldspar, 72. 
Osmosis, 44, 46. 
Over-irrigation, waste accompanying 

practice, 106. 
Overstocking pastures, 309. 
Ovule, 35. 
Oxygen : 

and life, 10, 41, 42. 

as an agent in soil formation, 78. 

liberation by plants, 43. 

limits growth, 49. 

use to plants, 42. 



Palisade cells, 34. 
Panicle, 37. 



Index 



443 



Paris green, 344. 
Parts of flower, 359. 
Pastures : 

alfalfa, 267, 304. 

definition of, 302. 

for different animals, 307. 

grasses used for, 304. 

importance of, 303. 

improving, 308. 

management of, 310. 

mixed grass, 304. 

native grass, 304. 

on dry-farms, 306. 

ordinary conditions, 308. 

origin, 302. 

overstocking, 309. 

permanent, 302. 

qualities of, 303. 

temporary, 303. 

wheat-grass, 304. 
Pathology of plants and animals, 4. 
Peaches, 349, 385. 
Peanuts, 284. 
Pearl millet, 331. 
Pears, 349. 
Peas, 349. 
Pericycle, 32. 
Permanent agriculture and minerals 

in soil, 125. 
Persian clover, 275. 
Pests, 20. 

Phloem, 30, 32, 33. 
Phosphate of lime, 73. 
Phosphorus : 

fertilizers, sources, 128. 

its importance, 43, 122. 
Phosphorus-loving crops, 119, 136. 
Photosynthesis, 42. 
Pigweeds, 367. 
Pistil, 36. 

Planning a rotation, important fac- 
tors in, 153. 
Planning the farm, 381. 
Planning work, 391. 
Plant and animal pathology, 4. 
Plant-breeding, development of, 364. 
Plant compounds useful to man, 54. 
Plant-food : 

and productivity of soils, 124. 

availability of, 121. 

balance needed, 125. 



Plant-food : 

control of, 10. 

in organic matter, 124. 

in soils, 120. 

manufacture of, 43. 

method of transferring, 48. 

of the soil, old theories, 118. 

removed by crops, 122. 
Plant indicators of soil acidity, 157. 
Plant parts and their functions, 27. 
Plants : 

adaptation to environment, 12, 21, 
4S, 149. 

and animals, their interdependence, 
51. 

as affected by sunlight, 18. 

as agents in soil formation, 79. 

ash of, 56. 

content of carbohydrates, 55. 

control of, by planting and pruning, 
62. 

difference in food demands, 119, 
136. 

how injured by alkali, 156. 

in relation to winds, 19. 

man's interest- in, 50, 52. 

use of carbon dioxide by, 42, 43, 57. 
Plant structure, necessity for study, 

23. 
Plasma membrane, 25. 
Plastids, 25, 34. 
Plowing : 

injury to wet land, 84. 

objects of, 146, 148. 
Plows, compared, 150. 
Pod corn, 197. 
Pop corn, 196. 
Poppies, 351. 

Potash-containing minerals, 71. 
Potash feldspar, 71. 
Potassium, 43. 

a limiting factor, 123. 

as fertilizer, 129. 

fertilizers, sources, 129. 
Potassium-lo\'ing crops, 119, 136. 
Potato, 224, 361. 

acre-yields, 228. 

adaptations, 228. 

blight, 237. 

cultivation, 234. 

cultural requirement.^, 224. 



444 



Index 



Potato : 

description, 225. 

digger, 396. 

diseases, 236, 238. 

distribution, 228. 

early crop, 233. 

harvesting, 235. 

history, 224. 

insects, 236. 

internal brown spot, 238. 

marketing, 235. 

pests, 236. 

planting, 233. 

relationships, 225. 

second growth, 238. 

seed-bed, 230. 

seed cutting, 233. 

seed selection, 231. 

storage, 235. 

uses, 239. 

varieties, 227. 

yield, 228. 
Preventing erosion, 158. 
Productivity in land valuation, 163. 
Profits, man and horse labor, 403, 404. 
Properties of soils affected by texture, 

81. 
Protein compounds, 43. 

composition, 56. 

concentration by animals, 59. 

occurrence in plants, 56, 60. 

uses to animals, 56. 
Protoplasm, 24. 
Pruning, 62. 

Pteridophytes or ferns, 26. 
Pumpkins, 349. 

Pyroxene, composition and impor- 
tance, 71. 



Quack-grass, 358. 
Quality in wheat, 182. 
Quality of wheat and climate, 183. 
Quartz, proportion of earth made of, 
71. 

R 
Rape, 343. 

enemies of, 343. 

or cowpeas with corn, 203. 
Real specific gravity, 86. 



Reclamation of alkali lands, 156. 
Red clover, 271. 

adaptation, 273. 

description, 272. 

distribution, 272. 

harvesting, 273. 

history, 271. 

importance, 271. 

" sickness." 271. 

value, 273. 
Redtop, 292, 304. 

adaptation, 292. 

culture, 293. 

description, 292. 

value and use, 293. 
Regions for hard wheat, 172. 
Relation of corn to other cereals, 191. 
Relation of plants to their environ- 
ment, 9. 
Relationship of cereals, 168. 
Reproduction of plants, 359. 
Reserve food in animals and plants, 

59, 60. 
Respiration, 41, 42. 
Response of plants to peculiar en- 
vironment, 49. 
Rhizoctonia, 238. 
Rice, 221. 

description, 221. 

harvesting, 221. 

history, 221. 

production of world, 221. 

uses, 221. 
Rivers, their importance in soil for- 
mation, 76. 
Rock : 

definition of, 70. 

soil-forming, 73. 

weathering agents, 74. 
Rolling land, efTect on moisture, 150. 
Roof -gardens, 351. 
Roots, 27. 

adjustability of, 27. 

cap of, 28. 

crops, plants included, 241. 

development of corn, 191. 

development of wheat, 168. 

general characteristics, 241. 

growing section of, 28. 

hair, 27, 44, 46. 

system, of alfalfa, 30, 258. 



Index 



445 



Rootstocks or underground stems, 

37. 
Rosette of potatoes, 238. 
Rotation of crops : 

and plant-food, 119. 

benefits from, 151. 

principles to guide in, 153, 
Rotation, planning a, 133, 
Rubber, 351. 
Russian thistle, 358, 359. 

dispersion of, 181. 
Rust of wheat, 180. 
Rutabagas, 253. 

culture, 253. 

description, 253. 

seeding, 254. 

use and value, 254. 
Rye, 219. 

adaptation, 220. 

description, 219. 

distribution, 219, 220. 

field treatment, 220. 

history, 219. 

seeding, 220. 

uses, 220. 
Rye-grass, 301, 304. 



S 



Sagebrush, 367. 
Salt-grass, 301, 304. 
Salts : 

diffusion of, 45. 

for spray, 376. 

injurious to plants, 155. 

sodium, injurious, 155. 
Sampling soils for analysis, 120. 
Sandstone, 71. 
Sanfoin, 284. 
Sap, rate of movement in plants, 

49. 
Scab, potatoes, 238. 
Schist, 72. 
Seasonal adaptability of crops and 

profitable production, 13. 
Season, length of, and crop produc- 
tion, 12. 
Seaweeds, 26. 
Second-foot defined, 103. 
Sedentary soils, 79. 
Sedges, 301, 304. 



Seed: 

definition, 359. 

essentials of good, 365. 

growth and description, 37. 

home-grown, 231. 

production of alfalfa, 269. 

selection for corn, 200. 

selection for potatoes, 231. 

storage of food in, 60. 
Seed-bed for grain, preparation of, 

175, 199. 
Seeding blue-grass, 294. 
Selecting machinery, 394. 
Selection : 

artificial, 360. 

methods of, 358. 

natural, 359, 360. 

of crops, 361. 
Serpentine, 72. 
Serradella, 284. 
Shape of fields, 384. 
Sheath of grass leaf, 170. 
Siberian alfalfa, 261. 
Siderite, 73. 
Sieve tubes, 33, 48. 
Silica, minerals composed of, 71, 72. 
Sisal, 341. 
Size of : 

fields, 384. 

machinery, 395. 

soil particles, 82. 
Slender wheat-grass, 301. 
Small-grains, 364. 
Smooth brome-grass, 304, 397. 

adaptation, 297. 

culture, 297. 

description, 297. 

harvesting, 298. 

value and use, 298. 
Smut : 

closed or stinking, 179. 

description of, 179. 

loose, 180. 

treatment for, 176. 
Snow as an agent in soil formation, 

76. 
Soda feldspars, 71. 
Sodium salts, injurious effects on 

plants, 155. 
Soft or flour corn, 197. 
Soft wheat regions, 171. 



446 



Index 



Soil: 

acidity and crop production, 157. 

acidity corrected by lime, 157. 

aeration, 86. 

bacteria, 139. 

classification, 79. 

condition, effect on crops, 68. 

definition of, 67. 

depth and structure in land valua- 
tion, 162. 

erosion, factors effecting, 158. 

exhaustion by crops, 123. 

factors, influencing plants, 19. 

formation, action of atmosphere, 
78. 

formation by heat and cold, 74. 

formation, by ice, 77. 

formation, by plants, 79. 

formation, by rivers, 76. 

formation, snow an agent in, 76. 

forming minerals, 70, 71. 

forming rocks, 73. 

management, need of up-to-date 
methods in, 69. 

moisture and soil heat, 9, 18. 

particles, size of, 82. 

particles, tillage affected by, 81. 

permanence of, 68. 

suited to dry-farming, 113. 

texture and surface area, 83. 

thickness and composition of, 67. 

water as agent in forming, 75. 
Soiling, 302. 

advantages of, 313. 

conditions favoring, 312. 

crop management for, 316. 

definition, 312. 

disadvantages of, 312. 
Soils : 

agents active in formation of, 74. 

amount of plant-food in, 120. 

analysis of, 119. 

blowing of, 160. 

classification of, 79. 

composition of, 119. 

depletion of fertility by leaching, 
123. 

determining fertilizer needs of, 127. 

each one a problem, 154. 

evaporation from, 95. 

exhaustion of, 123. 



Soils: 

formed by wind, 78. 

for wheat, 174. 

judging of, 161. 

named according to size of par- 
ticles, 82. 

not inexhaustible, 125. 

not suited for dry-farndng, 113. 

of glacial origin, 78. 

origin and composition, 70, 81. 

sedentary, 79. 

sour soils, 157. 

correction of, 157. 

texture of, 81. 
Solvent action of water, 76. 
Sorghum : 

adaptation, 323. 

broom-corn, 323. 

cultivation, 325. 

description, 320. 

distribution, 323. 

enemies, 328. 

grain, 322. 

harvesting, 326. 

history, 319. 

marketing, 328. 

planting, 325. 

relationships, 320. 

sweet, 322. 

uses and value, 327. 

varieties of classification, 322. 

yields, 326. 
Sorghums and millets, 318. 

importance on dry-farms, 319. 
Sow-thistle, Perennial, 358. 
Soybeans, 282. 

adaptation, 283. 

culture, 283. 

description, 282. 

harvesting, 283. 

value as feed, 283. 
Specialization, 383. 
Specialization of cells, 26. 
Specialization of functions in higher 

plants, 39. 
Specialties, 389. 
Species defined, 26. 
Specific gra\aty of soils, 86. 
Spermatophytes or seed plants, 26. 
Spike, 37. 
Spike of wheat described, 170. 



Index 



447 



Sprays, 376. 

carbolic acid, 376. 

copper sulfate, 376. 

corrosive sublimate, 377. 

iron sulfate, 377. 

salt, 376. 
Squash, 349. 
Stamens, 36. 

Standard of living and wheat, 184. 
Starch : 

manufacture by plants, 43. 

produced by sunlight, 19. 

use by plants, 60. 
Stable crops, 382. 
Stem, 30, 33. 
Stigma, 36. 

Stinking or closed smut, 179. 
Stock on farm, 381. 
Stomata, 34. 
Stooling of wheat, 170. 
Storage : 

alfalfa, 265. 

beets, 250. 

corn, 205. 

crops, 405. 

food by plants, 60. 

of grain from pests, 185. 

of manure, 133. 

potatoes, 235, 236. 
Structure : 

complexity of, in soils, 84. 

factors affecting, 84. 

of cells,' 24, 25. 

of soil and cultivation, 145. 

of soil and land value, 162. 

of soils, definition, 83. 
Structure and tilth, 84. 
Structure of plant, 23. 
Struggle for existence, 50. 
Style, 36. 

Sub-irrigation, 104. 
Sub-soil of arid and humid regions 

compared, SI. 
Successful farming, 406. 
Sudan-grass, description, 329. 

culture, 329. 
Sugar : 

analysis of in sugar-cane, 346. 

change to starch, 43. 

manufacture, 251. 

storage in plants, 61. 



Sugar-beets, 241. 

adaptation, 243. 

alkali resistance, 245. 

blight, 248. 

cultivation, 247. 

description, 243. 

diseases, 248. 

harvesting, 347, 349. 

heart -rot, 248. 

history, 241. 

insect pests, 249. 

irrigating, 247. 

leaf-spot, 248. 

marketing, 250. 

pests, 249. 

relation to good farming, 250. 

seed and seeding, 247. 

seed-bed preparation, 245. 

storing, 250. 

thinning, 247. 

use and value, 250. 

weed troubles, 248, 249. 
Sugar-cane, 356. 

analysis of sugar from, 347. 

description, 347. 

distribution, 347. 
Sugar in plants, 61, 250. 

wheat, 184, 185. 
Sulfur uses by plants, 43. 
Sunlight, and starch production, 19. 

effect on plants, IS. 
Sunshine, the means of all life, 59. 
Sweet clover, 274. 

control of, 181. 
Sweet corn, 196. 
Sweet potatoes, 347. 

adaptation, 347. 

distribution, 347. 

use, 347. 



Talc, composition, 72. 

Tall meadow oat-grass, 299, 304. 

Tangier peas, 284. 

Tap-roots, 30. 

Tea, 351. 

Temperature : 

and elevation, 16. 

daily fluctuations, 16. 

relation to winds, 19. 



448 



Index 



Temporary pastures, 303. 
Terracing to prevent washing of 

soils, 159. 
Texture of soil and water retention, 

92, 93. 
Texture of soils, 81, 82. 
Thallophytes, 26. 
Theories of plant-food, 118. 
Thistle : 

Canada, 358. 

Russian, 358, 359. 
Tillage : 

as affected by size of soil particles, 
81. 

objects of in dry -farming, 116. 
Tilth and structure, 84. 
Timber crops, 361. 
Timothy, 288, 304. 

adaptation, 289. 

culture, 289. 

description, 288. 

enemies, 292. 

harvest, 290. 

origin, 288. 

planting, 290. 

states producing, 289. 

value, 291. 
Tissue, definition of, 25. 
Tobacco, 344. 

culture of, 346. 

curing, 346. 

distribution, 345. 

marketing, .346. 
Topography in land valuation, 161. 
Total heat, 16. 
Tracheal tubes, 29, 30, 48. 
Transferring plant-food, 48. 
Translocation of food in plants, 38. 
Transpiration, 46. 
Transportation within plants, 48. 
Transported soils, 79. 
Trefoil, bird's-foot, 284. 

yellow, 275. 
Tropical fruits, 351. 
Truck crops, 349. 
Tull, Jethro, 44. 
Tumbleweed, 371. 
Tumbling mustard, 359. 
Turnips : 

culture, 253. 

description, 253. 



Turnips: 

seeding, 253. 

use and value, 254. 
Type of farming, 402. 
Types of corn, 195. 

U 

Underground stems, 37. 
Use of : 

alfalfa, 266. 

amendments for alkali, 126. 

blue-grass, 294. 

brome-grass, smooth, 298. 

carbohydrates by plants, 55, 56. 

clover, 255. 

cotton, 337. 

fats and oils, 57. 

field peas, 277. 

flax, 340. 

herbicides, 376. 

lime for acid soil, 157. 

mangels, 252. 

oats, 213. 

orchard-grass, 296. 

potatoes, 239. 

proteins to animals, 56. 

red clover, 273. 

redtop, 293. 

rice, 221. 

rutabagas, 254. 

rye, 220. 

soil analysis, 127. 

sugar-beets, 250. 

sweet potatoes, 347. 

turnips, 254. 

vetch, 284. 

water by plants, 47, 96. 

wheat, 183, 280. 
Useful products of former plants, 52. 



Vacuoles, 25. 
Value of : 

alfalfa, 261, 266. 

analysis of soil, 127. 

bacteria, 142. 

barley, 219. 

beans, 280. 

brome-grass, smooth, 298. 



Index 



449 



Value of: 

corn, 195, 197, 205. 

farm manure, 133. 

field-peas, 277. 

flax, .340. 

land and productivity, 163. 

land as affected by vegetation, 
161. 

land, things that help show, 161, 
162. 

lime for acid soil, 157. 

millet, 330. 

potatoes, 239. 

proteins, 56. 

red clover, 271, 273. 

redtop, 293. 

rice, 221. 

rutabagas, 254. 

rye, 220. 

soybeans, 283. 

sugar-beets, 250. 

the soil to man, 67, 68. 

timothy, 291. 

turnips, 254. 

vetch, 284. 

wheat, 183. 

zeolites, 72. 
Variation, law of, 359, 360. 
Varieties of : 

alfalfa, 261. 

barley, 216. 

corn, 195, 197. 

cotton, 334. 

potatoes, 227, 228. 

sorghums, 322. 

wheat, 171, 172. 
Varieties of wheat : 

number of, 172. 

objects in improvement, 172. 
Variety tests, 362. 
Vegetable fiber, 333. 
Vegetation in land valuation, 161. 
Velvet beans, 284. 
Venation of mono- and di-cotyledon- 

ous plants, 35. 
Vetch, 283. 

adaptation, 284. 

culture, 284. 

description, 284. 

seeding, 294. 

value, 284. 
2g 



W 

Washing of soil, prevented by crop- 
ping, 158. 

by terracing, 159. 
Waste lands, 386. 
Waste of irrigation water, 106. 
Waste of water by plants, 48. 
Water, advantages of control by 
irrigation, 98. 

amount to use, 104. 

and development of plants, 10. 

as an agent in soil formation, 75. 

as a plant-food, 119, 136. 

cost of dry matter, 47. 

disadvantage of control by irriga- 
tion, 100. 

economic problems in arid regions, 
106. 

effect of rolling on, 150. 

entrance into plant, 44, 46. 

factors affecting amount needed, 
49. 

function of, in plants, 55. 

holding capacity and soil texture, 
83. 

how lost, 94. 

in field soils, factors controlling 
amount, 93. 

in green plants, proportion of total 
weight, 55. 

injury by, 95. 

injury by over-irrigation, 104. 

in relation to plant growth, 16, 17. 

measuring of, 102, 103. 

methods of applying, 103. 

methods of expressing amount, 94. 

of the soil, its great importance, 90. 

origin and control, 90. 

solvent action of, 76. 

table, defined, 95. 

three classes of, in soil, 91. 

used by plants, amount, 47, 48, 96. 
Water-logged soils, reason for poor 

yields, 87. 
Water-loving plants, 16, 21. 
Webworms, 344. 
Weeds : 

and beet pests, 24, 248. 

annual, 368. 

best time to eradicate, 148. 



450 



Index 



Weeds: 

biennial, 367. 

control, 372. 

cultivating for destroying, 373. 

definition, 366, 367. 

eradictaion of, 373. 

history, 366. 

injurious to wheat, ISl. 

injury done by, 147, 371. 

introduction of, 369. 

laws, 373. 

losses from, 370. 

methods of destruction, 375. 

occurrence, 368. 

of: 

alfalfa, 267. 

beets, 248. 

potatoes, 236. 

sugar-beets, 248, 249. 

wheat, 181. 
perennial, 368. 
poisonous, 371. 
rotation of crops helps eradicate, 

376. 
spraying for, 376. 
summer-fallowing for, 376. 
Western wheat-grass, 301. 
Wheat : 

and standard of living, 184. 

amount to sow, 176. 

distribution, 173. 

Durum, 362. 

exchanged, 189. 

factors determining quality, 183. 

flour, 171, 182. 

geographical origin, 167. 

grades of, 188. 

growth above ground, 170. 

hardiness, regions affecting, 171, 

172. 
harvesting, 178. 
history of cultivation, 167. 
improved varieties, 172. 
insect pests of, 180. 
joint worm, 181. 
kernel described, 170. 
loss by not grading, 189. 
marketing, 187. 
origin of word, 167. 
pests, 180. 
preparaing for planting, 175, 176. 



Wheat: 

quality in, 182. 

regions for soft, 171. 

relationships, 168. 

root development, 168. 

rust, 180. 

seed-bed preparation, 175. 

.smut, 176, 179, 180. 

soils for, 174. 

speculation, 189. 

spike described, 170. 

storage of, 184, 185. 

Turkey red, 362. 

use and value, 183. 

varieties, 171. 

weeds injurious to, 181. 
Wheat-grass, 301, 304. 
When to apply irrigation water, 105. 
White clover, 274. 
Wind, action in soil formation, 78. 
Wind in relation to plants, 19. 
Wind regulates temperature, 19. 
Worms, cabbage, 344. 



X 



Xylem, 29, 30, 33. 



Yellow trefoil, 275. 
Yield of : 

alfalfa, 262, 263. 

alfalfa seed, 263. 

barley, 216. 

beans, 280. 

Bermuda-grass, 300. 

blue-grass, 294. 

buckwheat, 223. 

cabbage, 343. 

carrots, 255. 

corn, 197, 198, 199, 201. 

cotton, 335, 336. 

cowpeas, 282. 

crops relation to soil condition, 68. 

emmer, 222. 

field-peas, 271. 

flax, 338. 

forage crops, 291. 

Johnson-grass, 301. 

kale, 343. 



Index 



451 



Yield of: 

lessened by weeds, 370. 

mangel-wurzels, 252. 

millet, 330, 331. 

oat-grass, 299. 

oats, 210, 211, 212. 

orchard-grass, 295, 296. 

pearl millet, 331. 

peiiicillaria, 331. 

poor and good, 353, 355, 358, 365. 

rape, 354. 

red clover, 272, 273. 

redtop, 293. 

rice, 221. 

rutabagas, 254. 

rye, 219. 

soiling crops, 312, 313, 314. 

soybeans, 283. 



Yield of: 

Sudan-grass, 329. 
sugar-beets, 245. 
sugar-cane, 347. 
sweet clover, 275. 
sweet potatoes, 349. 
teosinte, 331. 
timothy, 2S9, 290, 291= 
tobacco, 345. 
turnips, 254. 
vetch, 284. 
white clover, 274. 



Zeolites, composition and importance, 
72. 



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